Arcane, Fire or Ice for mages?

Aggro is only for instance as said.

Fire is good for levelling, but you're sat drinking almost as much as killing, Frost is also the same, but you take a little longer to kill things, however you're not sat drinking as much, due to the Mana cost being reduced alot more in Frost than in Fire.

Also with Frost you get the chance to shield yourself alot more often, and at the cost of less mana too. This is a luxury Fire does not have.