Miller's problem is that he is a man without a true position like Percy Harvin. Urban's offense churns out these great athletes that don't have refined skills in the pro game. If you play Miller at WR you will spend most of his first contract teaching him the nuances of the position. I don't think he is a viable pro QB with his shoulder, plus he hasn't run a pro style offense yet.
For every Antonio Rendle-El and Denard Robinson, there a lot Pat Whites and Eric Crouches. Harvin is on his fourth team because he's a jerk but also because he doesn't have a true position. Anyone wish they had spent a premium pick on Terrelle Pryor as a WR?