Originally Posted by SRose
You first need to understand why she does the rubbing. Horses show dominance in a herd by getting the other horse to move their feet. When she rubs on you she is trying to move you and show her dominance. Continue to correct her every time she does it, even if it becomes a chore. Add on at the end making her move. You'll be showing her that she can't move you but you can move her. This can be simply by making her back up, to the side, whatever the environment allows you to do. Just stick with it. The stepping on your feet is her invading your space. She doesn't mean to do it but she should not be that close to you that it happens. Keep her out of your space. If she moves close to you without you asking, move her back. You'll need to do some groundwork with her to work on her awareness of your space. If you want her close to you, she needs to be invited in and then love up on her to show that it's ok if she's respectful to be close to you. Finally the pawing, this is usually an impatient habit horses use when board or not getting what they want. If she paws simply correct her, you can move her around for this too. I usually just give a deep, stern "quit" when a horse that I've been working with paws. This is after they've gotten use to me and my voice from training too.
Horses don't rub on each other to make them move. Sorry, but that is completely wrong. To make a more submissive horse move away, a dominant horse uses body language - effectively pushing them out of their space without touching them most of the time. They will also bite and kick.
This horse is more than likely just rubbing sweaty, itchy spots on her face. OP - don't let her do it, it is disrespectful of her, but mostly it is just plain dangerous, as you are discovering with the bit hitting you. Horses have big heavy heads, and humans are comparatively very frail. Get after her and make her believe that rubbing on you results in all sorts of hell raining down on her, and you will both be happier.
Once she isn't rubbing on you, then you can deal with the reason - the itchiness on her face. After a ride, I usually spend five or ten minutes scratching the face of the horse I rode, working into all the areas that the bridle goes on, and help out with that itch.