Heh heh. I'd like to see what ya got.
Black Company is a little odd, I'll admit. I think it COULD work for something other than BC, but the more I work with it the more I realize that you'll need to do some fancy work.
About 5th-6th level, casters can get a little ... disgusting.
Yesterday the party's wizard totally changed the face of an encounter by memorizing an 11d8 25' radius frost burst in the morning. DC 60, I think. He had to expend two points of spell energy to pull it off, but pull it off he did. Darn near knocked him out, since the nonlethal drain definately exceeded his cap (knockout chance in my game) but he used an AP to help make the MDT save and had enough juice left over to toss down a 6d4 frostie.
Wasn't expected.
I'm waiting expectantly for the spellcasting supp, myself. I've got a few I've been using, but they don't fully mesh with D&D spells. Specifically, as I said, those that map with caster level for damage purposes. Unfortunately, I don't think keeping caster levels exceedingly low FIXES it too much because then all other spells have exceedingly low durations and the like, even further limiting the use of non-combat spells.
--fje