You should try ProfitUI Reborn, download is
here. The group window is superior to the default in terms of size and overall group health visibility, as the players' bars are stacked closer together, with the cure icons to the side.
Your own health bar is also in the group window, and F1-F6 are to the left of every person's name. Click-to-cure is enabled in the group window, as well as the player window, and you can cure yourself via either window. This functionality does not require you to change targets, as I believe it does take advantage of the /useabilityonplayer command you mentioned.
The group window also has the ability to either queue your cure after your current spell finishes casting, or cancel your current spell and cure immediately.