You don't really need fiery attack (I think? never self-bursted)
Try slow fiery on pet GS attack?
I don't know. My advice would be for you to get 3 fires and 1 water. I'm sure if you ask on world somebody will help you with GS and the quests are fairly easy. You must do the Xao Lan quest, the sleeping pig in Kelan, the wolves in south(or north idk? >_< where kelan village is), the sleeping sheep near the barn and the bartender up-stairs of the bar from Holy village and some ship vouchers for going to Korea from the singer near the barn, then you could try google the burst guide.
It should give you LOTS more exp.