Yep, Turnoi. First class advice, as usual. Pulling a runner isn't to be done lightly as, as you say, as it can have bad and unforeseen financial and punitive consequences. It's like many medicines that have negative side-effects.
I agree with you that prospective runner-pullers should not allow their negative emotions and outrage lead them into making decisions that will result in their jumping from the frying pan into the proverbial fire.
Another factor to be taken into account is that foreigners have varying levels of what they can tolerate. An awful situation worthy of doing a bunk in the eyes of one foreigner might well be accepted as bearable by his fellow foreign teacher.
I think that a foreigner with a mind to run in the night should discuss his (or her) mental plight with a trustworthy foreign colleague, but on no account with a Chinese colleague. Chinese teachers love conveying that kind of thing to their fellow staff, to the workplace FAO, and even to the director. The Chinese working in the education sector are scandalmongers and people of low morals whom one can't trust. Betrayal of confidences is nothing to them!