This may not be a particularly huge issue for many players, but I have been annoyed by how goofy targeting can be and I feel this solution is very nice.

In other FF games, if you wanted to cast a spell on other characters, you simply selected the ability and an arrow would appear in the party member list allowing the player to select the individual by moving up/down and hitting enter.

In FFXIV, after selecting your spell, you must then move your cursor left/right or up/down through a 3D world with moving objects. Imagine if in other FF games the individual party members would move around the screen as you tried to select them.

Here is a particular example that I'm sure many people can relate with:
While doing leves @ Camp Broken Water on my THM, I had attempted to cast Sacrifice II on my Marauder party member. As I shifted from selecting the spell to selecting my party member, another party happened to run past my camera. Although I was able to cycle through all the players and eventually cast the spell, it was a rather frustrating process.
I think a simple solution however would solve this problem entirely:
After selecting a beneficial skill, the player would have 2 'fields' to select from. Both the 3D world by using left/right on the D-pad, and by hitting up/down on the D-pad the selection will move to the 'party field' which would be represented by the already present party member display and an arrow pointing to the individual currently selected. Simple, effective, and a little FF-esque.