Join Date: Sep 2009
Location: Tampa Bay area, FL
My OTTB also does this some days--for a few months after I brought him to his new home, he was very particular about me stepping in to his neck region (his "head space") As long as I stood at or behind his shoulder, I could touch him, brush him, etc but if I tried to stand in line with where I was brushing, he would pin his ears and give me a stink eye, which later turned in pinning his ears and giving me a warning head turn.
The combination I used was time and firmness. I get him some time to get used to me, so for awhile I respected his wishes and was careful around him, and then when I thought he should be respecting me, I started giving him a very firm NO and tugging on the cross ties to wake him up. When he was persistent, I would poke him in the shoulder.
My OTTB also did the same things that you're describing with his bit. I used a plain snaffle, and he would yawn and gape his mouth, wag his tongue, put his tongue between his teeth when he closed his mouth and try with all of his might to push the bit out once I finally got it in. I switched him to a hackamore and he's perfect now. Before I decided to use the hackamore though, I was contemplating getting him a bit with a port to allow some room for his tongue and see if that helped any.
To this day he's still not a huge fan of me touching/rubbing his face though, and he hates to have his muzzle touched or played with.