All I can say is that I relate to almost every comment in this thread. It's all true.
I've learned to keep my head down, do all of the paperwork/tasks as fast and poorly as possible, and avoid getting too chummy with anyone (farang/thai/filipino/whatever). Teach well, go home, and leave work at work. It's sad because that's "not how things ought to be" in this field and industry, but that's the reality of Thailand.
For anyone dumb (more likely desperate) enough to work for an agency, keep applying for direct hire jobs. Agencies amplify almost every single problem by somehow being even more self-serving and psychopathic than government directors.