Yeah, I really don't do the modifiers for click casting. I really dislike click casting in the first place but it's useful for cures. These were the two mods in question, link is from the development site:
http://www.wowace.com/addons/grid/
http://www.curse.com/addons/wow/clique
I have Clique set up to cast a cure spell on right click on the frame. Other players set it up to use shift, control and alt modifiers, as well as both right and left click, but I'm too lazy for that.
All of my healing spells were macros. All I had to do was move my mouse and press a keybind.
I can understand why they made the restrictions that they did here in EQ2 but it makes some things a bit more difficult. WoW's UI is completely done in .xml and .lua.
Edit for clarity, Grid is just a frame replacement. It does not have click casting in it natively; you need to install a separate plugin for it.