We must distinguish between different types of law and teaching. There are certain laws and precepts that are ceremonial and customary practices, or merely disciplinary rules. These can be changed, and are changed from time to time. For example, things such as the kinds and types of vestments and other regalia worn by the clergy and other merely ceremonial aspects of the liturgy can be changed. Disciplinary norms such as curial structures, canonical penalties, etc. can also be changed. 
 
But in matters of defined doctrine by the Magisterium regarding faith and morals, rooted in Scripture and Apostolic Tradition, or from previous Popes and Councils, the Pope is bound to uphold them. There are some technical debates about what is definitively taught that are too technical to set forth in this short answer. But the two matters, which you cite, are certainly teachings to which the Pope is bound and may not overturn.

The more common word for acedia is “sloth,” one of the seven deadly sins. Unfortunately, most simply equate sloth with laziness. Although sloth can manifest as laziness, it manifests other aspects as well. 
 
Fundamentally, sloth is a sorrow or sadness, an aversion, toward the good things that God is offering us. And thus, the Catechism teaches, Acedia or spiritual sloth, goes so far as to refuse the joy that comes from God, and to be repelled by divine goodness. (# 2094). 
 
The proper response to the good things that God offers us is joy. We should be joyful at the offer of a holy life, set free from sin and gloriously open to the love of God and others. 
 
But the sinful drive of sloth influences many to respond to this offer with sadness and aversion. Perhaps it would involve too many changes, and many prefer to avoid change and fear it. Frankly, many like their sins, preferring to indulge their lower nature. Sloth therefore perceives God's gracious offer as a threat and moves to oppose it. We do this in obvious and subtle ways. 
 
While sloth often manifests as a kind of boredom, aversion, or laziness toward spiritual things, one can also see it at work in the kind of frantic indulgence and workaholism common today. Indeed, many indulge in an excessive activism in the world of politics, career, business, and other worldly pursuits. In no way are they lazy, but they often use frantic activism to avoid the spiritual contemplation of God or the things of God. The claim becomes, “I am too busy to pray, get to Church, or attend to moral and spiritual reflection, the reading of Scripture or the study of my faith. Such people are not lazy, per se, but they are averse to spiritual things and prefer worldly pursuits. And this too is sloth. 
 
Thus, sloth is best understood as a sorrow or aversion to the good things that God offers. It is a deep and sinful drive rooted in a disordered preference for passing worldly things. We must ask for a joy for spiritual and eternal things and zeal to cultivate a deeper desire for God and the things of heaven, for our fallen flesh is strongly opposed to the desires of the spirit (cf Gal 5:17).

Perhaps you would agree that if someone loves someone else, that love would not include him forcing his will on the other. And while it is certainly true that the Lord wills to save everyone, he does not force us to accept his. God is not a slave driver, he is Love and love invites us to freely accept his offer of an eternal relationship. 
 
While some think that everyone wants to go to heaven, generally they have a heaven in mind of their own design. But the real heaven is not merely a human paradise; it is the Kingdom of God and all its fullness. In heaven is celebrated: Charity, worship of God, truth, chastity, forgiveness, esteem of the poor, humility etc. And yet there are many who reject some or all of these values. Why would a loving God force people to enter into the eternal place which celebrates things they reject? 
 
Hence, the existence of Hell is not opposed to God's love. It is in conformity with the respect necessary for our freedom to accept or reject the relationship of love. Mysteriously, many come to a place in their life where they definitively reject God, and the values of the Kingdom he offers.

You are quoting Romans 6:10 which says, "the death he died, he died to sin, once for all.” In saying that Christ “died to sin,” St. Paul is not saying he died on account of his own personal sins. The Greek word hamartia (Sin), Is often used by St. Paul to refer to our own personal sins. But it is also used to refer in a more collective sense to the sin of the world. For, this fallen world of ours, is immersed in sin, in an attitude of rebellion pride, greed, lust, and so forth. And this climate of sin, is like a force, a mindset, initiated by Satan, and connived in by human beings. It is to this world of sin that Christ died. He broke its back, by dying to it, and rising victorious over it. And he defeated it in the most paradoxical way: he conquered pride, by humility, disobedience by obedience, and death, by dying and rising. 
 
It is to this regime of sin, that Christ died, not his own personal sins of which scripture is clear, he had none. (cf 1 Peter 2: 22) 
 
In the same chapter (6:2, 11), we are taught to realize that we too have died to sin, and that this world of sin is to have no more power over us. We must come to experience increasing power, authority, and victory over the influence of this world of sin. We are to lay hold of the life which Christ offers us wherein this world of sin has no more power over us.

The resurrection accounts in the gospels do have some differences in detail. How many women went out to the tomb that morning, one (Jn 20:21), two (Matt 28:1), or three (Mk 16:1)? How many angels did they see that morning, one (Matt 28:2; Mk 16:5) or two (Lk 24:4; Jn 20:12)? Did the women run to the disciples and tell what they had seen (Mt 28:8; Lk 24:9) or did they say nothing out of fear (Mk 16:8)? Did Jesus see them first in Galilee (Mk 16:7; Mt 28:9) or in Jerusalem (Lk 24:36)? Among the Apostles, did he appear to Peter first (Lk 24:34), all eleven at once (Mt. 28:16), or the eleven minus Thomas (Jn 20:24)? Did Jesus appear to them in a room (Jn 20:19) or a mountaintop (Mt 28:16)? Lastly, did Jesus ascend on Easter Sunday (Lk 24:50-53; Mk 16:19) or forty days later (Acts 1:3-9)? 
 
Most of these apparent discrepancies are not actual conflicts upon closer examination and are easily explained. We cannot look at them all in a short column. But as to your specific question, it would seem most likely that several women went out that morning. That John only focuses on Magdalene is not a denial that others were there. Matthew and Mark, in saying two or three may not be engaging in a headcount per se, but engaging in generalization, such as when we say words like, couple or several. 
 
We should not be surprised that there are some differences in the accounts. Even today, eyewitnesses of an event often emphasize certain details and have different recollections as to the particulars. People often summarize longer stories as well and speak only of essentials. This does not mean that the event did not happen or that unmentioned details by one person is in conflict with details mentioned by another. Given the numerous times Jesus appeared and the many people who saw him, we should not be surprised to find certain differences in the accounts. In this light the differences actually lend credibility to the gospel accounts, which do not try to paper over them, but realistically report them. (See Catechism #s 642-643)

The date of Easter varies each year because it is linked to the cycle of the Moon, relative to the cycle of the Sun. In order to set the date of Easter one must first look for the vernal (spring) equinox, which is March 20. The word “equinox” refers to that time when the length of day and night are equal. It is also the date we set for the official beginning of spring. 
 
Having set our sights on March 20, we next look for the first full moon following March 20. Some years, the first full moon occurs quickly, within days of the equinox. Other years it occurs weeks later. 
 
For the Jewish people, this first full moon after the equinox also signaled Passover. And since it was at the Passover feast that our Lord Jesus suffered and died and rose, we Christians always fix Easter to coincide with Passover. 
 
So then, Easter, (which is always on a Sunday since Christ rose on the first day of the week), is celebrated on the Sunday following the full moon after the vernal equinox. 
 
Historically there were great debates within the Church in the East and the West about setting the date of Easter. The system described above was finally settled upon. But today, we still find that the exact date for Easter varies a bit in the western and eastern parts of the Church since many of the Eastern rites still use the more ancient Julian calendar, rather than the Gregorian calendar used by the church in the West. 
 
Your wish for a fixed Day for Easter, as is the case with Christmas and other feasts, is understandable. But as you can see, the relationship of the Moon relative to the sun doesn't fit perfectly into our modern systems of timekeeping and to fix the date as you suggest would probably open old debates that caused great harm in the early Church.

Your desire to pray this prayer is understandable, and good. The prayer can in fact be said. However, perhaps a little history and context is appropriate to understand why it fell away in the early 1970s. 
 
Historically, the liturgical movement beginning in the 1940s and continuing through the Second Vatican Council., sought to reemphasize the Eucharistic liturgy, by distinguishing it from some of the devotions that had grown up around it. The hope was to emphasize participation in the Mass as the greatest devotion. 
 
Among the devotions that attached themselves were a number of prayers said following the dismissal from Mass. Thus, although the priest turned and said Ite Missa est (Go the mass is ended), this was not exactly so. First there was a blessing, then a recitation of the last Gospel, and then after most masses, prayers, which included the prayer to Saint Michael. In many parishes Benediction of the Blessed Sacrament was also done. 
 
Liturgists of the time sensed that lesser devotions following the greatest devotion somehow implied an inadequacy in the prayer of holy Mass. 
 
Whether or not you agree with all these points, it was the thinking at the time, which led to the elimination of many, if not all, devotions immediately following the Mass. 
 
That said, you and fellow parishioners, are not forbidden from praying certain prayers and devotions following mass, even with the priest. It is best however, to allow those who need to depart, e.g. for work, to leave prior to the beginning of devotions. Otherwise, people feel trapped, and the instruction that they may go, is lost or reduced in meaning. 
 
Please also be aware, while the St. Michael Prayer is an important prayer, many others also insist on other devotions for similar reasons. Thus some pastors are reticent in fostering such public devotions, since requests tend to multiply. So pastoral discretion is needed, and solutions will vary from parish to parish.

No, you ought not attend. Both of them are bound to have their marriage witnessed by a priest or deacon in the sacred setting of the Church. In celebrating the marriage outside the church without permission, they are entering into an invalid marriage. To attend, and to celebrate with them, signals support of this sinful action. 
 
While these sorts of situations are awkward, you are not the source of the awkwardness, they are. A firm line is appropriate in such serious matters which underscores the sinfulness of the situation. 
 
Your explanation to them of your incapacity to attend should be done charitably, leaving the door open for further discussions leading to convalidation in the near future, should they still go forward with their plans. 
 
Finally, avoid harsh debates with other family members who may still go. While attendance at such weddings is strongly discouraged, Church Law does not absolutely forbid it given the human complexities involved in such situations. Some respect for prudential judgments that differ is appropriate. 

No, they are not equivalent. There are degrees to mortal sin just like there are degrees to venial sin. First‐degree murder is more grave than missing Mass, or viewing pornography, or any other grave sin that we might imagine. 
 
It is true that killing someone and missing Mass are in the same category of "mortal," (or grave) sin. But they are no more equivalent, than a rat is equivalent to or the same as a man, simply because they are in the same category "mammal." 
 
Your description of both sins as being punishable by eternity in Hell also implies an equivalence by that fact. However, a distinction is necessary regarding the way you connect the notion of eternity to punishment. That one is in Hell eternally, is not due to punishment per se. Rather, the eternity of Hell (or heaven for that matter) exists because, at some point, our decision for or against God, and the laws and values of his Kingdom becomes a decision that is for us at death forever fixed. Thus, that Hell is eternal, is not by itself a gauge of the punishment involved. 
 
We need not presume that everyone experiences Hell in exactly the same way, any more than we presume that everyone experiences heaven in exactly the same way. There may in fact be degrees of suffering in Hell, and degrees of glory in Heaven. 
 
While there are mysteries involved here, it makes sense that there are some Saints who, on account of extraordinary virtue, have a greater capacity to appreciate God's glory in heaven. It also makes sense that for those in Hell who have rejected God, and his Kingdom, there would be degrees of suffering experienced, related to how deep their rejection of the light is. Scripture indicates we are judged according to what we have done (Revelation 20:11‐15). Thus, there is at least implied some relationship of reward or punishment rooted in what we have done or not done. Jesus also speaks of places of special honor in heaven, indicating levels of some sort in the afterlife (cf Matt 20:23).

Irritation of this sort is perhaps understandable, when a phrase gets picked up and used widely in multivariate ways, and thereby comes to be seen more as a slogan than as informative. 
 
That said, the New Evangelization is officially used to mean several rather specific things. First it is new, in the sense that we, as a Church, cannot afford to do business as usual. We must behave in new ways. We can no longer be content to sit within our four walls and talk about the faith among ourselves; we must go out. We cannot simply think that evangelization is opening the doors and hoping people come. If there ever was a kind of inertia that brought people to church, that is not so now. It is clear that we must go into the community, into the culture, and re-propose the gospel. In this sense, “everything old is new again.” For the new evangelization seeks to go back to Christ’s initial Instruction, "Go unto all the nations and make disciples…” (Matthew 28:19). 
 
New evangelization also appreciates that we cannot simply say what we believe, we must explain why, and show its reasonableness. Perhaps in previous times, it was sufficient to argue from authority, but these days, people want to know why, not just what. 
 
Thirdly, evangelization is “new” in that we must vigorously engage in all the new ways of communicating that have exploded on the scene today. We must creatively engage all these new forms of communication, along with the traditional modes of communication, such as writing, cinema, radio and so forth.