I am guessing the answer to most of these questions is no, but I am going to do my diligence and get some feedback anyway.

I lived in China from 2001-2004 and for about the first year and a half of that time I was working for a school in Chengdu, which apparently does not exist anymore. I was working on an F visa. I was not aware that this was strictly illegal as the only three other westerners I knew in Chengdu were all teaching on F visas. It was described back then to me as "quasi-legal".

I am now looking to return and work on a proper z visa. In your opinion:

Would the government recognize that as teaching experience towards my two years? (my guess is no here)

Would the school I go to recognize this as working experience?

Would they even find a 13-year-old experience relevant?

Does a claim of prior experience require some kind of letter from that previous employer?

If anyone has dealt with presenting work experience from a school that has closed what was involved in that?

If you were in my shoes, would you mention this to the school when applying for work or just say you have no prior teaching experience?

One concern is that the school would simply not recognize it. The more troubling concern is that it could be information used as leverage for them to break the contract as they see fit. Am I off base in thinking that? Does anyone have a "friend of a friend" who has used F visa teaching experience on a resume before?

Thanks in advance.