7. After Michael's death who would replace him as unquestioned head of the family?
Surely not Tom. He lacked the muscle and personal force to be the new boss. He'd also have to face much stronger opposition in Rocco and Neri. No way would they bow to him.
I believe part of Roth's strategy, had the Tahoe shooting succeeded, was to pit the members of the family against each other for succession. That would have had them fighting each other--to his advantage.