I am kind of a WoW refuge. I started playing FFXIV just before HW was released, so I consider myself at least a partial veteran. For this post I'm going to assume a couple of things. 1. My idea probably won't apply to console players. I don't have a clue how to play this game on a console so if I'm wrong, I'm wrong. 2. PC players who play healers most likely use mouse-over macros for healing.
When I healed in WoW I often used a healing add-on, such as Healbot or Vudoo. Before anyone starts saying those add-ons heal for you I want to set the record straight. They do not heal for you. All they do is provide a simpler interface for mouse-over healing. You open the add-on and assign healing spells to a mouse button or a keyboard/mouse combo. It saves a lot of time instead of having to type out all of the mouse-over macros.
Now I'm not suggesting that FFXIV start allowing add-ons. I like the fact that it doesn't. But I've always wondered why none of the MMO's I ever played have adopted an interface like this. Would you like it if FFXIV had this type of healing interface?