Born from my unending dislike of Earth = Acid. Where did that come from, anyways?

Alternative Elemental Tradition (Metamagic)
There are many different ways to look at the world and classify it; the basic elemental system is only one.

Prerequisites: Ability to use an elemental or energy effect

Benefit: When casting an energy spell or an elemental spell with an energy component, using a spell-like ability, racial trait, power, class feature, or supernatural ability, you have the option of replacing the normal results with the following:

Original Associated Energy
New Associated Energy

The Air allows sound to grace your ears, and the molten core of the Earth casts a warmth that endures any winter. Corrosive liquids fall under Water’s care, and sky-fire forged in the volcano god’s smithy carries the same heat as what burns in your hearth.

Making the replacement turns spell’s casting time or the time required to use an ability into a full-round action (unless it was a swift or immediate action, which are left unchanged).

Special: Many elemental and energy spells have a secondary effect; making suitable effects for all possible spells is beyond the scope of this post, and you should consult with the DM before taking this feat.

True Elementalism
You don’t clumsily associate element and energy like the common mage. You instead draw upon raw, true elements surpassing anything the Material Plane has to offer… although none but the Elemental Planes could truly contain them, anyways.

Prerequisites: Ability to use an elemental or energy effect, 7 hit dice

Benefits: You use the pure elements, the physical manifestation of the concept of the element, in the casting of elemental or energy spells, spell-like abilities, powers, class features, racial traits, and supernatural abilities. Any spell with the Air or Electricity descriptors deals pure Aerial Damage; Earth or Acid descriptors deals pure Earthen damage; Water or Cold descriptors deal pure Hydrous damage; those with the fire descriptor deal pure Incineration damage.

Any effect dealing Aerial, Earthen, Hydrous, or Incineration damage, when used on any plane other than an elemental plane, deals only half damage—however, very few creatures can resist, much less ignore, the pure element damage types. If used on its respective plane (Air for Aerial, Earth for Earthen, Fire for Incineration, Water for Hydrous), it does full damage—but any creature with the same subtype as the element takes no damage. If used on any of the other three planes, it is reduced to dealing 1/4th damage, and no damage at all to natives with the same subtype as the element.

Elementals, regardless of plane, take no damage from effects born from the same element as them, and take 150% damage from other pure elements.

Special: Some spells dealing energy damage have no connection to the element (i.e. Acid Arrow), and are not subject to this feat. Some spells have secondary effects accompanying their elemental or energy damage; such effects may need to be altered by the DM.

Elemental High
Using elemental magic sends a rush of tinted magic through your veins, to which adrenaline has no compare.
Prerequisites: Ability to cast elemental spells or use elemental spell-like abilities
Benefits: For one round after you use an elemental spell/spell-like ability, you benefit from the leftover magic coursing through your body.
-Air Magic: You gain a +1 deflection modifier to AC against ranged attacks and a +10 foot bonus to speed.
-Earth Magic: You gain a +1 bonus to natural armor and damage reduction 2/-.
-Fire Magic: You gain a fiery touch; any melee attack against you or melee attack against someone else deals 1d6 fire damage to the opponent.
-Water Magic: You gain 4 temporary hit points and can breath water.