I agree on almost everything, especially feats to AVOID, but I don't agree that empower is necessary for all casters. Wizard's main power is his high DCs and mainly death spells, thus not relying on raw power, so for him empower can be skipped, as long as you have maximize for mobs that are immune to death or just bosses.
I also think that heighten is a must even for earth savant, you still have DCs on some of your conjuration spells, you'll want to heighten web as well, and have SOME means of death spells and even enchantment, as low as your DC will be, they can come in extremely handy.
I'd take Heighten on an Earth Savant for Flesh to Stone and Web. No reason you shouldn't have a couple of solid CC capabilities, especially things like F2S which puts people in a 50% damage state.
Ghallanda - now with fewer alts and more ghostbane