Ok, here's a mock-up of what you guys are suggesting with all stacks expanded, in whooping 2560x1440 resolution no less:
[Linked Image]

-Warrior skills went through the roof, I imagine others will as well in final release when we will get a full set of them
-Icons obscure the view, can be quite annoying in combat even with only one stack expanded

So, I dunno, looks clunky to me. I still think that hotbar expansion is better, but this mock-up is better than using those skills from skills window.