i like the premise and most parts of this creation, however i agree with Reality Glitch, with the discription you gave i would say that they shouldnt have a list of spells they know, instead they should gain an ability that lets them combine other spells of lower levels or decompose higher level ones to find new spells, thus each higher level spell is = 2 of the slot below, and each unique combination/spell will have only that one equation, so no spaming 2 lvl 1 into lvl 2s into lvl 3s and backwards, but it could be unique for each caster (maybe a dm random spell roll?) any whoo, good job sofar, keep up the work