No, I don't think it is mid-life crisis, I think it is just his personality. DH is a bit arrogant, or at least he comes off that way. Since the EA, that has toned down quite a bit. The thing is, he has cause to be a bit arrogant. He is a well-educated genius and pretty fine to look at, too. However, he isn't perfect and I take him down a few notches occasionally when he gets too arrogant.
I like your idea of doing something for the less fortunate. Don't just give $$, actually work with them face to face. I don't know if that will change anything though.
When you say conceited, is it that he feels good about himself or that he thinks he is better than other people?
I decided to edit my comments here.