I totally agree with you re dress code. Teachers should be made to look like teachers in the classroom. They should not look like backpackers and hippies! Here, my fellow FT is running around with a little backpack on his back. He does so wherever he goes, rushing around like a headless chicken, his weird behavior affording great amusement to the students, I guess. But the school leaders will surely look down on this strange behavior, which Chinese teachers would never adopt. Too many foreign teachers here are not real teachers. That's why they don't know how to dress and behave as real teachers do.
Chinese teaching assistants in class. I agree with that. They can be interpreters as well as ensuring that the FT is not spreading Western propaganda to China's young minds. A fellow FT told me that his students had told him a loopy American was playing 'religious games' with her students - enacting biblical stories, it seems. Talk about naive! Guess she won't last long - TA present, or not!