4) revenge, who knows maybe he wanted to really stick it to some people, think about it, he could be sitting somewhere, and finally realizing who he can and cant trust, all the people who betrayed him who are now kissing his ass, and all those that he thought he could trust, who are now trying to scam money off of his estate.
Does Michael feel like the kind of person that holds a grudge against others, and that is all about revenge?
Not to me. He was very betrayed but was still all about love. Ofcourse he learned he couldn't trust everybody, and ofcourse he got more careful, with whom to surround himself with, but I don't feel that he is a man, that is all about revenge and payback. I'm not saying you're wrong, it just doesn't fit my picture of him.