Detect life, light, dispel, rage/calm; why was I the only guy ever to use these spells? It always struck me as absurd, as I sneaked towards the necromancer boss (I forget his name) that all of his minions, despite much speculation on the habits of rats and wind, never once thought to cast a detect life spell or illuminate that dark corner. When I cast rage upon one of them, the others never thought to try and dispel it.
So what I'm saying is, give enemy mages the tools to user/counter these spells. In Oblivion rage was so useful that it was broken. You just kept on casting it until you only had one weakened enemy left. Detect life would help them fight stealth, and could even be a counter for 100% chameleon; a mage casts detect life to find me, then casts a marking spell that lets everyone else see me too.