Wimbush is the best running QB ND has had since Tony Rice. The gameplan should be developed around what he does well. If it is, he'll be fine. If they continue to try and make him a pocket passer, he will struggle. It's OK to call some passing plays, but he should be coached to run if his first 2 reads aren't there. Given the slowness of his progressions and the struggles of the OL, he should never be throwing to the 3rd or 4th option. He should simply tuck it and run.
The coaching staff needs to determine what the identity of the team will be. If they are determined to through the ball from the pocket for the majority of the offenisve snaps then they should go ahead and make the switch to Book.