Nerve Staple will Stun the enemy for two to three rounds, and taka a decent chunk off their health. I is very useful to get a few squares between oneself and the enemy as a caster.
Crystal Healing will create 9 squares of tiny crystals, giving back 5 HP each when walked on. It can be a life-saver if one has walked into an acid bolt trap or drank form a fountain of acid (which do about floor +3 damage per round for six rounds, enough to kill many characters).
Psychokinetic Push offers unexpected applications: You can not only push enemies, you can also push things. Such as traps, chests, lights, rocks or shrines. This can be useful to barricade monster zoos, or set up Burglary skills better and most importantly: Push traps out of your way if you cannot disarm them.
Crystal Healing and Psychokinetic Push make this the anti-trap skill of choice for pure mages.