If I were the Niners, I wouldn't risk the potential downside. There's no questioning his talent, but with all the other issues they have to address this off-season, I think they should work on rebuilding other parts of the roster. I guess if the FO were to make the gamble on Jimmy G's full recovery by September, they might go for it. But I don't know if it makes him any more worth the potential drama if they end up struggling to win games.
The Colts have an ungodly amount of cap space, so I sincerely doubt money will be an issue. They already have established talent in Hilton, meaning more headaches for defensive planners. Luck is a great option to be catching passes from at this stage in his career. I could also see Houston in the mix, but I don't know how much space they're going to lose in a restructured deal with Clowney. Both teams are also far more prepared, in my opinion, for a deep playoff push than SF or Oakland. AB likes to win, and we've seen these types of scenarios unfold enough times in the past to know how divas behave once their new team fails to meet expectations.
As for the second question, unequivocally...NO. Miami has so many needs, and they've had more than their fair share of diva personalities over the last decade. I'd rather see them lose than watch yet another locker room drama play out.