I've pondered the warden's heals on my hotkeys... right now my brain is overloaded on work so i'm not thinking too hard, but I imagine needing a ctrl-1/6 hotbar setup and possibly getting a 3rd arm grafted onto my chest ... Once i get my 4x4 up and running and i get configured for 6-boxing (like you, on 2 machines), i'll be forced to figure it out and post the results here.

For now, this setup works great w/ a Mystic... But for druid heals.... well, let us know if you figure it out!