Numerical CD timer on quickslots. So many times I go to use an ability only to find that it still has 5seconds CD left, only problem is that I cant see the tiny thin dark line.
Buff/Debuff Timers or Bard Would be good if we have the option to enlarge the buff/debuff icons or have them somewhere else. Also the option to make it so you can only see you own debuff's on the target.
Proc Messages I dont care if its just similar to floating combat test, but if you gain a buff (bloodthirst) a little +Bloodthirst then -Bloodthirst coming off you like healing would be good.
Added another Quickslot bar at the bottom I dont know about anyone else but I hate using the left/right side for my keybindings, sure its fine for mounts/quicktravel/stims/buffs but for skills that I have to keep an eye on CD's I want all in one place.
Thats all I can think of atm, Added the ability to use mods would be sweet, but I know the argument against that is that ppl will make mods to make encounters easier with ability timers etc. but not all mods are like that, these few ideas are examples of some.