I don't believe that the 'Chinese losing face thing' comes into the equation at all. It's clear that Yuming knows full-well that each year they will have trouble with many of their foreign teachers and that most of them will leave under a cloud- it's all grist for the mill for them, and whereas that little Chinese personess in charge may well get niggled with the antics of surly and ungrateful FT's, she certainly won't lose any sleep over it- she might try and mess things up for you visa-wise etc., but that's just entertainment and light-relief for her, and you shouldn't take it personally. You mean sod-all to her, she doesn't give a tinker's curse what you think- she's met hundreds of your type before and knows she'll meet many more. You will easily be replaced-many of those replacements will cause little personess trouble and they'll be replaced in their turn. I don't think she is likely to dislike foreigners in particular- those and the Chinese staff are all considered rubbish-an unfortunate business expense, putting it euphemistically.

Is Yuming at risk of collapsing? Not a bit of it, even if criticisms expand ten-fold on the internet.

In the distant future when many more Chinese schools want foreigners for the good of their students, things might change; sadly, most of us are employed for promotional purposes, which is the main reason why you can't discipline the kids at any of Yumings schools-you are not there for your teaching skills.