Actually, I don't know if this is feasible, but..
Put 1 point in Quad Blow and max the other two skills, since you're going to get a better quintuple blow in 3rd...
Everything but drain, You can use potions, I mean they drop a whole lot more often, and it's much easier to cover costs, Especially with potion mastery.
Go with either 17SB/6BD or 20SB/3BD. My friend (lv. 121) says he has 3 BD and DOESN'T USE HP POTS.
He says that "3 Drain is good enough."
Personally, I do not know, as I have yet to get a Battle Mage to 30, but my friend is lv. 121, so he can't be doing much wrong.
(He got to 120 before the bandana event ended.)