I don't play anymore, if I ever come back I'll let you know.
FS INT? Pure INT, no STA needed. Try maxing out the key skills, Heal, Haste, Heap Up are the best. From that Beef Up, Cannonball, Cat Like Reflxes
Ugh, I don't have a Blade so I can't really help you a lot. But if you go to Flyff forums on their site, they have amazing guides.
You can still go BP, but if you go INT and STA in the beginning you can't really fight by yourself since you have no Str to fight with. So you should level as a FS and at 60 become a BP and then continue leveling like a FS until you can get that AoE. Its faster leveling like a FS so might as well take advantage of it.