I reckon even after the killings, Michael still could have finished college and gotten a law degree Vito still could have used the Corleone magic in Little Italy for lawyer Michael to run for congress but he chose to drag him into Mafia

He could never hand over “his life's work” to Clemenza and Tessio even after promising them they could form their own family


No doubt legitimacy was the biggest problem
It was Vito's “goal” So how do you figure Michael's long-term plan was legitimacy?

Vito and Tom have talked many times about Michael's future He didn't know of Pop's plans for ("Senator Corleone...Governor Corleone") until the garden scene

He was pretty determined to go his own way, away from the family business That's my family, Kay It's not me until the attempt on Vito's life So I reckon he would do the same when Sonny lost his life
Vito may not have to uproot him He would have volunteered like he did to kill Sollozzo and McCluskey

He told Kay about the bandleader's story
If Clemenza knew that the 'old man' thought Michael was the best of his sons, the one who would surely inherit the family business." what good a law degree would be for Mafioso Michael especially when time is of the essence

If he knew, hothead Sonny could have too leading to conflict and possible violence (like Fredo), even before anything happened