@OP: for controller targetting, while my lazy self just macros my three whole offensive spells to <t> and then <tt> so the only retargetting i ever really need to do is up/down on the d-pad to swap between party members, that's not necessarily for everyone (yeah yeah it's weird and doesnt work for maximum optimal rotations, oh nooooo). still keeps the option to specifically target and attack stuff as well.

for less lazy folks i recommend binding something like R3 to target-of-target (and getting very acquainted with the controller targetting scheme's finer points), to more easily allow you to swap between healing and offense, at least.