I don't know if anyone who will or would be capable of doing anything will read this but the one single thing I would change and which aggravates me constantly is having to fiddle with my loadouts to get the right spell/weapon/scroll or whatnot in the hand I want it to be in.
The game seems to be coded with a "smart" (not necessarily so) approach to equipping spells and equipment. Sometimes when you toggle a spell, weapon or shield it will wind up in the left hand, sometimes the right. Toggling choices sometimes give you right, left, both, or unequip but they NEVER give you ALL of those choices. depending on which spell/weapon/whatnot you may be limited to right or left, left or both, right or un-equip - etc. I have to fiddle, fiddle, fiddle to get a spell un-equipped to fight bare knuckles and due to the "last thing in the hands" when you attempt this - it makes it even worse.
There should be four simple toggles for every spell/weapon/etc:
1. Right
2. Left
3. Both
4. Un-equip
This is my only real mechanics gripe. without nit-picking.