I agree 100% on Neilsen. His forte coming from HS was that he could be a stretch four. I like the comparison to Wiltjer. He has shown some mobility and I agree that he has not shown a propensity to post up effectively.
I am not convinced that Kaufusi can not develop a low post game. He had not really played any basketball for almost four years until this past summer. I think that if he works hard he can be a guy that gets 10 points per game and be a good defender and rebounder.
Your points on Bartley are spot on and he confuses me more than any other player. I remember watching Abouo and thinking this guy should be an outside linebacker. Sometimes I think the same about Bartley. Very gifted athlete and can be a lock down defender. Bell is a much better shooter but here is hoping Bartley improves in that area.