Beware the blacklisted thing... though there is a local Ombudsman that I heard a laowai successfully appealed to after his school threatened to fire and blacklist him.
When you sign your contract you should also sign a secondary one which regards his sort-of judge.
Of course, we're all just pawns here and no doubt, like Dragonized rightly said, there must be better places around the world to teach and treated equally, albeit difficult to find.
As for worker rights, come on, no matter how great is our live in China and what we say on this and any other forum website, you just can't compare the "rights" in China with the far superior worker protection rights found in most Western countries. No comparison.
That's why there is such a degree of luck involved in finding a non-bastard employer to teach/work for in China!
It's the country, lifestyle and he'hem,,, girls, we mostly like! Cheap beer and cigarettes help too