How many hours a week will I be expected to work?
Most teachers here try not to do more than 16-20 'contact' hours per week with their principal employer. Any more than that could lead to burnout.
It's worth nothing that many schools in Thailand will want you on the premises for more than just your 'contact hour' teaching. There is an expectation that you'll hang around the school doing your preparation work, test-marking, etc. This could also be for the school to advertise the fact that it has foreign 'native-speaking' teachers.