I'd have to agree that if there's one player where it is really hard to see any potential for a bust, it's MPS.
The tools he has already developed should be moret han sufficient to make him a good player. He's a great skater, big and strong, competetive, excellent puck skilles, good playmaker, drives to the net, competetive. He doesn't have to develop into a big goal scorer to be an effective player - there is such a thing as a playmaking winger. For that matter, he has the tools to be a terrific two-way player, if someone should want to turn him into that. AFAICS, there is practically no projection involved - except as to whether he's going to be a star and not merely a good player.
I would say that everyone in the top ten apart from the top 3 have a much greater bust potential, in the way that there is more projection involved - will f.e. the physical dominance Kand and Schenn display in the WHL necessarily translate to the NHL, given that these are medium-sized players? Will Schenn be able to thrive with what amounts to pretty unexceptional skating without much explosiveness?
OEL is an excellent prospect, but he is not as far along the curve as MPS is, and hence, again, more projection. Kadri is a player with a somewhat similar style, but he does not have the physical tools MPS have and also not the same ability to use his teammates - more projection. Cowen, there you have the injury issue.
cheers