TB, as I've opined elsewhere, I think that Vito's view of life was radically different from that of most people. Regardless of the reason(s) why, there was a component of that view that incorporated murder as an infrequent but totally acceptable strategy. What struck me (in the novel) was his apparent loathing of America. I think he looked at America as simply a tree from which he could pick fruit.

No, he apparently didn't want Michael to enter the family business IN THE WAY HE AND SONNY AND FREDO DID AND WERE EXPECTED TO (emphasis added). However, he did want Michael to enter it as an adjunct, someone who as Senator Corleone or Governor Corleone could aid and abet the Corleone's nefarious enterprise. Vito's and Michael's view of legitimacy was to earn respect from the community; it was not to leave murder and mayhem behind.

Remember what Michael said to his son before he left for Florida: "Someday you will [help me]". Those words were frightening. As GF II and III played out, Michael just could not let go and he had to be forced to let Tony go.