Yes, it was as if the collapse of his own world made him more perceptive and caring of the world of others, specifically Alma Jr.'s. Some people turn bitter and hostile when life beats them down. I don't think we can term Ennis to be bitter in the end. I don't think it was bitterness at all. Certainly an element of resignation. Certainly an element of sadness. And most certainly: a loss of will to seek happiness for oneself, coupled with a will/desire to give happiness to others.
Yes,and this does have a certain logical; if his world had broken down,now a new beginning imposed over everything else.And this new beginning obliged him to learn from his former mistakes and faults.Among them there were doubtless the new perception and caring for the others,as you say;not forget the needs and wishes of the beloved ones who surrounded him,as he had made somehow with his family and,of course,with Jack.This is the real learning that bad and tragic moments should carry.