I think having the story be about the Corleone's & the Government is a SWEET idea! In GF II, they glanced over Vito's life, but didn't go too much into detail (like we see him as a kid in Ellis Island, and then the next scene he's already in his 20's and married). They really jumped and maybe they could talk about that. Maybe they could talk about his father being killed by the mafia, and then his brother. I don't know. But I think having the Corleone's & the Government angle could really work! That's just my 2 cents anways.