I'd use Streak/BallOfLightining over MistForm, its faster and has a stun. But I do have trouble finding a place for a Vamp skill to get that recovery.
DevouringSwarm/CloudingSwarm is useful, but I find a sorc is built for burst, not DOT, so IceComet or Atronach are better suited.
And then there is Invigorating Drain/Accelerating Drain, nice for a stun as its an instant cast and can be canceled, but if you hit them with this, you have granted immunity so CrystalShards wont knock them down.
I am playing around with them at the moment but find I always just cave and go for the Ultimate so it doesn't take up a normal skill slot.