Not saying I hate Annie but.....

That's going to cause more problems than it's worth. Her Q only has a 4 second cooldown. If she can cast that without requiring a target, she will be able to stack her passive really really fast. Even if you were to say, also remove her indefinite hold on her Stun.

Not only this, but honestly her stun should not be able to be held indefinitely. I believe she would be a much more balanced champion if after her stun is stored that she loses the ability to use it if she does not cast a spell within X seconds.