To clear something up, fire FS is NOT int based. My FS as a fire killer does the same as a lvl 17x rb fire wits. Also it's not pointless if your wanting to give damage to all enemies. I used to use it on instances like alex as a way to get rid of fire glazes and kill all enemies in 1-2 rounds before I got a crescent bow. It doesnt do a lot of damage but it can do enough to help make lower mobs die faster for quests/instances.

Also, if you go questing you'll realize there are more stars then you'll know what to do with. I have all skills on all chars (even DS for mages and FS for melee's) All 4 of my chars have 3 rb pets each and all still have 20+ stars still to use. The only place I never used stars was Yuna's amity in welling and Cursed Palace in Rome. Those are the only 2 real waste of stars in the game.