I'm going to attempt to help, even though I have no experience with CTR.
For the moving forward, I would just correct her with your hands every time she does it - while keeping your heel on her. If you take your heel off when she moves forward, she's going to think that's the right thing to do.
As for the slowing down (I do reining and want my horses to back fast, so I'm no expert here either)... I would try half-halts while backing. Or you could do actual halts - have her back one step, stop, back one step, stop, etc.
Hope that helps : ]