Atm whenever loot is picked up regardless of what it is, it populates the skill bar even if its locked. It's really annoying especially if you use Polymorph effects as they show up as new skills on the bar where there is space.
I propose that loot doesn't automatically show up on the skillbar if its locked and that a Polymorph skills effect skill replaces the Polymorph skill on the bar rather than showing up as a new skill on the bar (IE - Spread Your Wings is replaced with Flight on the Bar while active).