Gem use question.

[archaeolept]

he can also have his spell casting level increased through communion.

as to using gems, I believe a mage can use up to 2 gems per innate level of ability. as such, if you wish your Air-1 mage to cast an Air-2 spell (a free one, not one which itself costs any gems), just script the spell and give him a gem. well, giving him two would be safer - as gems can also be used to lower the fatigue costs of the spell.