A little behind on this, thanks to the pressures of work etc. So plainly back surgery for Booty will have him missing spring practice. I don't know that this matters all that much. If misfortune trails Booty, then pleny of reps for Sanchez will be some help for general risk mitigation.
Frankly, I don't think that it's going to matter too much which QB starts against Arkansas or Nebraska: not that they won't play hard, but unless there's a dramatic improvement in Razorback and Cornhusker form, and provided that SC's offensive line doesn't completely blow, it should be okay for either QB. As the season progresses, that will be less true.
LA Times coverage seems to indicate that the linebackers are getting healthy and improving, which is a plus. Still, I'd be happier to read that there has been some stand-out at corner and tailback.