Generally, the norms of the Church indicate that the altar should be fixed, that is, immovable, made of stone, and located in the sanctuary of the Church, that is, in an area of the church distinguished from where the people gather and are seated. (“Built of Living Stones” 54, 57) 

At first glance, it would seem that your pastor is operating outside these norms and that the appropriate place for him to celebrate Mass is at the main altar of the church. 

Sometimes however, in older, or larger churches, the pastoral challenge you described is present. In such cases the use of a smaller altar, closer to the people, (as is done in some larger basilicas), is employed. 

The movable altar should be truly noble, not a simple folding table, and dedicated to no other purpose other than the celebration of the sacred liturgy. While this is not ideal, in some instances it may be pastorally allowable, especially if recourse to a chapel for daily Mass is not possible.

It is perhaps too absolute to say the Church has "an answer" to suffering, and why God permits it. The full answer to this is ultimately mysterious, and has many aspects, which are hidden from our view. 
 
To be sure, we do have elements of an answer, which God reveals to us, or which human reason can supply. One element of an answer is the existence of human freedom. One way God could prevent a lot of suffering would be to cancel human freedom whenever it was abused. But God, it would seem, does not usually see fit to do so, and his respect for our freedom is very consistent. 
 
Another aspect of an answer is that suffering often brings growth and opens new possibilities. Perhaps God sees these fruits and thereby allows some degree of suffering. 
 
But again, these insights are part of an answer. They do not constitute a full or complete answer to the great mystery of suffering and why God allows it. These insights tend to bring up even more questions. Fundamentally we must accept that we do not have an absolute answer to the problem of suffering. 
 
While it is fine that atheists raise this issue, (for it is a valid question we all have), the demand by them for an absolute answer is not reasonable. We must also ask them to consider that not everything has a simple answer. 
 
Thus, if they will demand that I must absolutely answer the question, “Why is there suffering?” then I would also like to ask them to give an absolute answer to the question, “Why is there love? Why is there generosity or a passion for justice or self‐sacrificing heroism?” 
 
If you and I must account for the negative side of suffering, then perhaps too our critics must account for the existence of love. If they are honest they will perhaps admit that while they can give a partial answer, they cannot fully account for these things. 
 
The bottom line is, not everything can be absolutely answered. To unreasonably demand answers from others, when they cannot supply them either, is not itself a rational or adequate reputation of the existence of God.