Star Ocean is a great game and I like his targetting system, but i don't think we can use that system in FF14, because it was inaccurate.
I prefer the second idea, but this means a click for every skill.
Another simple idea, be able to change a target with up/down, even if we have a locked target (before we choose a skill).
It becomes R1+ Up/down= target
left/right skills
R1+ start = party/enemy/all/friendy rotation.
edit:
or better
If we press X (without releasing) we can target another monster/player (all target mode?); releasing the X button the skill is activated.
What I normally do:
1- Lock a friendly target with "party" on (tanker).
2- click on an offensive skill. I'll have a subtarget.