I play with keyboard/mouse:
Since attack/block is bound to keys, and runes to 4 others, I would like to have a keybinds per character.
Here is why:
Most melee classes I use left mouse attack/ right mouse to block, middle mouse to shoulder barge.
However when playing a caster, I like to have leftmouse cast rune1, rightmouse cast rune2, middle mouse cast rune 3. And I just add attack under Q for destructibles.
Like in Diablo 2 you had keybinds per character, since there you hover over skills ingame to bind keys to skills. And this was saved per character.
Another thing I would like is to have scroll up/down available as key binds.
I know these would not work for hold key things, but would still be nice if the game allows these as keybinds.