Just from a game management standpoint he is sorely lacking. The two point conversion mistakes he's made numerous times at Notre Dame would get him crushed in the NFL. Notre Dame has been pretty poor on the margins throughout Kelly's era here as well, in other words they aren't good at the little things. The NFL is all about being good at the little things because the talent gap is so small.
If he can't succeed here then he needs a demotion to a lower level not a promotion to the highest level.