I don't want to come on as being mean or any thing. My mare had that done to her before I bought and she ended up being so headshy she would strike at you. I ahve gotten her over that now, but it was a big hurdle. Im ony saying this so you don't do more damage than good. I hate seeing good horses turn bad because of something accidential like this.
Hope everything works out for you.
Sorry for being mean if anyone thinks that.
For the trotting...circles circles cirlcles. All the fast horses that I've ridden slowed down when I did a circle.
For the bridleing...HAF if she needs her teeth done....get her teeth done. Whether or not you think it's bothering her doesn't mean it isn't or is. Something about the bit is bothering her...she's not accepting it for a reason! Are you banging the bit on her teeth? Are you yanking the bit in her mouth or hurting her mouth when you ride? That could make her not accept the bit because she knows what is going to happen.