What are some skills that you don't use?
1) Truth: too random for me.
2) Un-Truth: ditto.
3) Move on Lava: this is only usable on one dungeon. And even then I was using Move-Find.
4) Any Weather: I didn't even realize for the longest time that weather can affect the strength of elemental spells. But not enough for me to notice.
5) Jump +1 (or +2 or +3): you can increase jump with boots or just use Ignore Height.
6) Gained Exp Up: not useless, but if you master the jobs like me, you'll reach level 99 long before you master every job. I focus on increasing JP instead.
7) Equip Axe: I'm not enamored enough with axes to want them in non-Geomancer jobs.
8) Equip Knife: Ditto with Katanas.
9) Finger Guard: I don't fight Mediators often enough to want to protect against their attacks.
10) Face Up: Generally I don't mess much with Brave and Faith unless I'm treasure hunting. Most of my units have Brave and Faith of 70, which works fine.