The coaches not allowing him to throw doesn't mean you are correct. It could be because they sucked at playcalling (and they did), that they didn't trust him to make the proper read, they didn't trust their receivers to get open and for him to make a good pass, or that they never got around to it.
Moreover, , the coaches said he is healthy enough to throw. You can do a quick google search and read statements from Both Urban and Braxton. they don't need him to throw deep downfield. Any athlete has more than enough time to attempt a Tebow pass.
Colt McCoy didn't wash out of the NFL because he injured his arm. He washed out because he was a good college QB and his skills didn't translate to the league. The point I wanted to make was that running ATHs get hurt all the time, as do defensive players, offensive lineman, and heck even unlucky bystanders lol. The game of football is dangerous. If Braxton was as fragile as you say then he should be sitting in the stands or holding a clipboard. Like I said, he throws the ball more in practice and on his own and yet his arm didn't fall off. It's one or two passes a game....we aren't asking him to run the Baylor offense.