Valuable information, thank you.

I wonder if staying in the China on a 'cancelled' residency permit (given that the school went to the trouble of cancelling it), say teaching one semester instead of the contractual two, staying in the country for the duration of the annual permit rather than doing a round trip home for a tourist visa.

Flying domestically and checking into hotels with the cancelled residency permit would likely not be a problem, but leaving the country I'm quite sure the status of the cancelled residency would be discovered and fines levied. It used to be that the maximum fine for overstaying a visa was 5,000 rmb, still cheaper and less trouble than flying round trip to the states.