For Bailey to start, he will have to have a good pre snap read and get rid of the ball quickly. Will also have to improve his accuracy greatly on throwing the ball downfield. When you get a guy open deep, you can't miss that throw.
Salter is a freshman and has to get bigger. Will be interesting to see how quickly he progresses in spring practice. Will not be a good sign if he is the starter on opening day but, might get there by mid October.
Hooker is the wildcard. Big, athletic and experienced. Was Va Tech's starter before injuries and proved himself to have success with his athleticism. Not sure about his accuracy down the field and ability to read defenses.
With all of the different intangibles, the most accurate and successful passer is normally named the starter.