Probably worth pointing a few things out regarding realignment:
1. USF (and UCF for that matter) isn't going to be allowed into the ACC as long as Miami and Florida State are part of that conference no matter what the stadium/football program situation is. That's just not going to happen.
2. Pac-12 isn't going to expand into Florida or any other East Coast teams, because that would be dumb geographically and time zone wise, and insanely expensive due to travel costs.
3. SEC (see ACC). Florida may only have one vote, but as one of the SEC's crown jewel programs, they probably have enough clout to torpedo any USF/UCF ambitions for the conference.
4. Big10 - Certainly a possibility due to the Florida market, but they're definitely going to require an on campus stadium with at least 50-75k seating capacity, along with some consistent success in the football program
5. Big 12 - Still the most likely from a long term standpoint, but if UCF has success in the Big 12 and gains more political clout, they could make it very challenging for USF to get in the conference.