Wilson will obviously stay as the projected Starter.

Hall is the back up to a QB who has already missed half of the season with injuries.  He plays in an offense that values mobile QBs.  He also is on the baseball team and has a brother who has commited to BYU.  Jaren has 3 options:

1) He could stay and be garunteed at least a backup role and prabably at least a handful of starts.

2) He could transfer to a lower tier FBS program, sit out for a year, and try to battle for playing time (which is by no means a garuntee)

3) He could transfer to an FCS program. 

One other significant consideration is concussions.  Jaren has yet to complete a game without getting concussed.  Another concussion or two, and he may hang up his (football) cleats.  If that happens, staying at BYU means he can continue to play baseball and attend BYU.

Romney turned down a scholorship to Nevada to walk on to BYU.  I doubt he expected that he would become the starter here.  Doubtless he hoped for it and thought he'd at least have a chance to compete for playing time, but he knew what he was going up against and chose to walk on anyways.  

At this point in time, I think Baylor is more securely in BYU's corner than at any time previously.  He's been the QB for 2.5 games this season.  He's garunteed a scholorship at the end of this season.  The guy ahead of him (Hall) hasn't finish a game yet without being concussed and the starter has now missed half the season with injury.  For a guy who has already put playing with his brother and attending BYU ahead of probably playing time, I think that there is more than enought to keep Romney here.