There is a similar point you could make that was made with my pyromaniac class, about how if you have to negotiate with an outsider, your class probably deserves Diplomacy on its class skill list. I disagreed, but I gave the pyromancer Bluff because that's what I assumed he'd be doing, but you didn't give this guy I would pick one and give it to them.

Elemental Savant: There's going to be a bit of tricky wording here, but you should know that Piercing Cold specifically has no effect on creatures with the [cold] subtype. (It still pierces cold immunity, but not if the creature is immune to cold by being [cold]). However, Searing Spell does not have this restriction. So you'll need to work that into the ability somehow, that Piercing Cold doesn't help you deal full damage against a creature with the [cold] subtype.

Elemental Focus (Ex): Yikes. Definitely very little reason for someone to choose Fiery Heart over Icy Heart with this ability. Between Cold Focus, Greater Cold Focus and nine levels in this class, you're getting a +5 DC to all your [cold] spells.

Elemental Apotheosis: Nice! Very nice ability. However, I would note that if you are Large or Larger, you get a pair of slams instead of 1. (as Elementals do)

All in all, a good class. I like it.