There are so many potential builds that I want to play that are just too tedious because of constantly having to switch spells onto my hotbar to use them. 10 slots is way too few when things like Viking Wizardry or Warlockery have 6-7 activated spells by themselves. The need to actually be able to play the game without constantly switching skills in and out is becoming more of a build determiner than what I think would actually be best or most fun to play. Please give us a way to either have more slots on screen, or switch to one or two more sets of 10. The ability to have buff spells on one bar and attack spells on another, for example, would be really nice.
Maybe you guys could make it so that the number is adjustible. Like, grabbing one end of the hotbar and dragging could add hotbar slots (possibly to both sides, though I never use the inventory one).