1. THAT one is a tough one. It is in a WEIRD spot, I had to get a close friend of mine to play with the texture in order to be able to fix it on that head because I had the SAME problem. If you want, I might be able to let you borrow a 'corrected' preset head texture of mine so you can guide off of it if you'd like?
2. That's a common bug if you're using the OpenGL engine. When you load the game when the first window comes up [after the black box] go to the drop down and switch from "OpenGL" to "DirectX" and start. Some computers can't run DirectX very well [and sometimes the opposite happens and it runs better than it does on OpenGL] but the teeth texture glitch is fairly normal on OpenGL and that's about all you can do.