A few quality of life additions I would love to see:

• Being able to move while using potions. It doesn't make a whole lot of sense (in a game perspective) to stand still and heal, just to get hit by something else while standing still. It just adds an unnecessary level of difficulty due to way you have to place yourself. And it slows down gameplay in intense situations, which isn't really ideal either.
  -*Level overlay map. I've seen a lot of posts asking for this, and I fully agree. It doesn't feel right to play an ARPG without an overlay map. Would be ideal for it to have quest and possibly rare mob markers as well.
• Ability to move the left-click skill to the hotbar. Please.
• "Not enough resource" indication. Currently there is no way to know if you have enough resource to use a spell besides the line of red text that pops up after you've tried to cast the spell. Greying out the icon or something similar when you don't have enough resource would help a lot.
• Currently your character is being stopped when you try to use a spell without the required amount of resource, which is very annoying (especially with no indication if you have enough resource or not). Removing that would make gameplay a lot more fluid.

And finally, not really a "quality of life", but I think you should be closer to portals/level gateways to be able to use them. At the moment you can click on some of them without it being on screen if you hit the very corner of it, which you can do by accident, and it's instant so you can't even cancel it, resulting in being randomly teleported.