plaw, you're wonderful! (And good writer, too. This is already so much better than that Weingartner abomination.)
My advice would be to not do as many "update biographies" at the very beginning. The focus needs to be on Michael--how he deals with Fredo's death and Kay's departure. I think a strong focus should be on how he develops his relationships with his children--why Anthony rebels and Mary sticks with him. Another aspect: the Gaming Commission puts him in the "Black Book," and he has to deal with out-of-town Dons.
Too bad Weingartner poisoned the well here.