Very interesting analysis, Q.

In a deleted scene from GF, following Connie's wedding, Vito et al are preparing to visit Genco on his deathbed. Michael is very cold with Vito. When he tells his father that he's going to finish college, Vito says he approves of it. Vito also asks him to come to him as a son should. And, in the flashback scene at the end of II, Michael bridles when Tom tells him that he (Tom) and Vito have made plans for him. Michael seems like the classic rebellious son.

But when Michael woos Kay in New Hampshire, he tells her that his father is "like any other powerful man with responsibility for others," and implies that senators and governors have people killed. So, he seems to have adopted the idea that if they can be considered legitimate, so should Vito--and he.

To your analysis: was Michael's perennial quest for legitimacy a rationale for his behavior? Or, was it his way of trying to live up to his father's expectations for him that had been dashed when he killed Sol and Mac?

N.B.:
In the novel, Vito says that "a man has but one destiny." He was referring to Sonny's decision not to go to law school, but to follow him in the olive oil business. Did Michael have "but one destiny"?