I often use Quick-Heals to heal on my druid, and really the only one I have ever used. So I am not sure how others have worked.....
But it is pretty simple to say the least.
Example:
Left Click - Nourish
Mouse Wheel (Click) - Rejuv
Right Click - Regrowth
I can also use Shift, CTRL, or ALT for others along with any other mouse buttons I might use.
All I do is pretty much click on someones name with the appropriate button on my mouse that I choose and they heal.
What if Nui could do the same with the names that are on the bottom of the screen? Place my mouse over someones name and what ever I have macrod to my mouse it would buff (thorns or whatever else), heal, or cleanse (Diseases, curses, etc etc) that person? Perhaps if the person got a disease the box would turn blue, curse green, if they have agro it would be red? I am not sure if this is plausible, but I thought it was a pretty nifty idea.
I am also sure it would get rid of other addons not needed if this was the case.