Help balancing spells. [3.5]

[herrhauptmann]

I'm slowly working on a class in which the player can choose casting for 1 of the 4 classic elements: Earth, Air, Fire, and Water. The class (regardless of level) gets 3 spells at each level. Supposed to be an attack, a defense, and a utility/movement/debuff.
Problem is, I'm having trouble balancing the spells, both with each other, and with already existing spells.

Currently trying to work on the earth and air level 2 spells.
I'm currently using the Air one in playtest, so I'd rather change the earth spell to match it.

Air:
Lightning Blade: As the Wu Jen level 2 spell in complete arcane.
Levitate:
Wind Armor: Deflection bonus to armor, 1/ every 3 caster levels (2 at CL4, 3 at CL 7, etc). Doubled against nonmagical ranged attacks. Spell provides no bonus vs large projectiles like ballista bolts, catapults, and rocks thrown by giants. Abjuration[Air]. Range: Touch. 10 minutes/level

Earth:
Spike stones (minor): Standard Action. As spike stones, but 1d4 damage
Earthen Grasp-

Spoiler

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<Trans[earth], VSM(tiny clay hand), 1StdAct, Closerange, 2rnds/lvl, no save, SR applies> – A Medium-sized arm of soil rises from the targeted hex of earth or sand. It attempts to Grapple any creature in its hex or one that is adjacent. If not directed by the caster, it attacks randomly. The arm has a Strength of 14 + 1 per three caster levels. The arm can make one Grapple attempt per round and does generate an Attack of Opportunity. If successful, it attempts to Pin the target, which does (1d6+Strength modifier) hp of lethal damage each round. The arm has AC 15, Hardness 4, and 3 hp per Caster level.

Granite Hide: Abjuration (earth). Verbal, Somatic. Standard Action. Creature touched gains 1 Natural Armor +1 / 2 Cl (2 at CL3, 3 at CL 5, etc). Max of +5
Creatures without natural armor such as humans, count as if having Natural Armor +0 Lasts 1 hour per level.


Deflection vs Natural AC bonuses.
10min vs 1 hour.
Doubled against nonmagic ranged. Standard bonus against magic ranged. And useless against big ranged. Vs Always effective.
Technically no cap vs capped at 5.
+1 per 3CL vs +1 per 2CL.