Some random notes to put in on this version of me rules...

Firstly, I put the schools with the 3/2/1 costing from 2nd edition (Evoc, Trans, Conj 3 point, Ill, Ench, Abj 2 point and Div & Nec 1 point). Not necessarily for balance, but because I wanted sorcerors to be much more commonly seers and necromancers.

Secondly, Awareness gives a +2 to DCs of spells for me. Fairly beefy at all levels. Stacks with the focus feats.

As for the problem with casters in general.... they're still the best thing outside combat (short of skilly things) but due to various other changes too long to go into, in combat they get comprehensively owned. In fact, I'm considering beefing up the sorceror rules in to make them more competitive with fighter classes at high levels (mainly casting speed issues). That said, it'll wait until I've done some more serious playtesting.

Fundamentally, it's based on the idea of strong role balance rather than mechanical balance.