I agree with everything you posted, LW. But I don't think it's certain that Vito intended to bring Michael into the family business as his successor, or as Sonny's second-in-command. If Sonny had lived and held the fort until Vito recovered, Vito may have worked to bring Michael back to America, to finish college, to be a lawyer, and to work to legitimize the family.
I base my assumption that Vito intended to bring Michael back into the family business largely on a couple of clues from the film:
1. Vito's anger and disgust upon hearing that Michael killed McCluskey and Sollozzo. His reaction shows that Vito realizes his dream of Michael becoming "Senator Corleone, Governor Corleone" is dead.
2. Vito's comment that Sonny was a bad Don. While he says this after Sonny's death, he surely came to that conclusion much earlier (perhaps upon hearing about the retaliatory hit on Bruno Tattaglia). He also seems rather lukewarm to Tom's skills as
consigliere. Between the dissolution of his dreams for Michael's legitimate future and the succession problems facing the Family, it seems reasonable to think that Vito envisioned Michael returning to pull the strings behind Sonny and Tom.
