Not a chance the Rams are going to take a QB in the top two rounds with other much more pressing needs. The team is pretty committed to Sam, they want to lock him up long term, he's the one who wanted to delay it because he doesn't feel he's playing as well as he should be to maximize his value. Given that Sam was on pace for career bests this season with an even younger offense around him, I think that there's no reason, talent wise, that the Rams would want to replace him, and then essentially move back several squares so they can develop a young QB when they haven't finished with the development of another.
So unless Sam had some freaky medical issue, he'll be starting for the Rams next season. I don't foresee any reason why Bradford wont be healthy next year either, he had a clean tear, just the ACL, and has a very long time to recover and rehab. He'll be fine.
As for Fisher going to USC, that rumor was essentially debunked a while ago. Fisher has no interest in taking a demotion, and why should he?