I suspect that your former employer doesn't treat foreigners equally, namely those that disappoint their destination schools will be treated very badly.

I'd think so too - in the private sector it's all about making money. If you're good at teaching, they'll send you here and there to make them money. But you'll have limited free time though you'll be making extra money. However, what you're making will pale into insignificance when compared to what they're making off of YOUR hard work. I for one would NEVER be that kind of lackey in China!