My thoughts on possible changes.

Remove the blue circle from spells/items on CD. Just let it be greyed out with a number possibly. Let the item bar be moved from either side to the next? Move the team frames to the top left corner or back to the left wall. You could have left the kill counter at the top of the screen. That wasn't intrusive. ... That's pretty much it for me. Like I said in another post just make it more customizable.