i like this idea. It's true, the mage is so poweful. But is not fair that the mage is allowed to use all the spell with practically no drawback, its like a fighter able to use all the weapons in deep technics, if you must specialize in a weapon when you use weapons, why the mage have the feature to use all the spells with freedom? is not fair. May be, discuss this could make more diverse the mages because are all equal. I think that a specialist mage should count as the next magic circle in his specialization and a drawback of -6 in concentration when casting as a generalist, except necromancy muahahahahha*evil laugh*.Think this you can use all the spells, thats so powerful.