As Loosie's said, eliminate the possibility of pain. It may be pain upfront with the bit, or pain from behind which she's trying to evade and so isn't wanting to listen to you asking her to stop. Once pain is eliminated you could take a number of approaches.. Basics as Loosie's said are excellent. :)
One method which is often useful is reinforcing her lateral flextion so that she kinda re-relaises what pressure from the bit is telling her. HEAPS of one-rein stops are involved. First in walk then trot and canter. If she's really hard when you're trying to ask for the one rein stop, you may also need to get her really working off your leg so she gives into the pressure instead of fighting against it. You say she puts her head in the air so she's already fighting a bit, so perhaps she needs to soften through her body to be able to listen to what you're asking of her. Leg should help with this. Some people would fix your problem using the one-rein stop by applying quite a bit of force so that the horse realises instantly, and then they work back from using alot fo force to only the slightest amount of force, but as she's holding her head up in the air, I don't think using alot of force would help her. She would only be upset by it, so I'd keep things nice and quiet.
Another method is that when she doesn't listen to you asking for her to slow down that you simply keep her in that gait if not faster so that she tires (keep her going though) and as she tires more ask again for her to slow. It may take a while, so you might have to be prepared for some long sessions, but the idea is that the horse should realise that if she doesn't listen to you asking her to slow, that she can continue as she is, but that when she wants to slow she's not allowed to. Not until you ask for it anyways. Of course when she does slow, give HEAPS of praise This method does have it's limits though. And not everybody feels confident nor has a suitable area to conduct it.
The issues she has with standing can be solved by you simply enduring her little fidgeting. Saddle her up, mount and just stand around for a while. You can have her stand around for ages. If she moves around, just ask her not to nice and quietly. She may get frustrated, but she should get bored of her fidgeting and see that it's simpler for her to just stand there nicely. End on a good note of course. You'll need to do this more than once of course. :).
If her head up in the air when you're asking her to slow/cirlce etc isn't due to teeth or bit intolerancies, it may be just an accessory to her confusion if she's just not sure what you're asking of her when slowing/circling.
Goodluck :). Would love to hear back about how you get on. Especially if you come across something no-one mentions here that works for you. Am always interested in training techniques.