Never ever ban Transmutation, are you crazy? The top three banned schools are:
Evocation: you can get Contingency via Greater Shadow Evocation. Wall of foce you can live without. Everyting else is crap.
Enchantment: Save or lose spells, but since you are an Illusionist you have plenty of those. Save or lose are either good when going for maximum DC and basically being a one trick pony, or skipping them. Still, most of these are mind-affecting, which means they are crap at later levels.
Illusion: not appicible in your case.
Divination is not allowed to be banned.
Conjuration is simply awesome.
Transmutaion has fly, baleful polymorph, shapechange, disitnegrate... It's simply too good.
Necromancy has Ray of Enfeeblement, Ray of Dragon Rape (aka. why it's bad to have 14 dex vs a level 16 caster), finger of death...