When I saw your list I was shocked that you had only 1 Sr on defense. The following will be Sr next yr:
Turner - DE, Potter - DE, Steinkuhler - DT, Barfield - DT, Murrillo - DB. I've got to believe their senior years will all be better than this last year.
As for WR, I think Menelik Holt and Niles Paul will see a lot of time. If Chris Brooks was going to develop, he would have played much more this year.
QB battle will be interesting. Ganz may not have a lock on it because the new HC will probably (hopefully) install a simpler offense that doesn't take 3 yr to learn. Suspect Ganz, Lee and Witt will battle it out. Should be interesting.