I love the Ninja. But the job level I'm on with my Ninja is taking forever, like 450 AP.

I also think the Thief's "Steal" is important.

Blue Magic has come in super handy. There's a few bosses that are hit by "Death Claw", which leaves the enemy with only 1 or 2 HP. Also, the
Blowfish type move that always does 1000 damage is very valuble, for a long time. Also, White Wind is great for curing, too.

I've recently realized the Ranger is actually pretty good, which is something I personally haven't seen in many RPGs, you know, to have a powerful, useful Archer class.