I have never met either of you. But I am reading this from an outside perspective.

First, you claim it is impossible to work in China without a Z visa, this is false. It is possible, just not 100% legal, but possible! For example, I could be on an F visa and work two part time jobs. These part-time employers are not required to provide me with Z visas and so on.

Second you claim the teacher wants a fake certification? I'm sorry but I doubt there is any ESL teacher in the world that would ask a Chinese person to help them get a fake certification. You would probably be the last person this person would ask that to. Really all they need to do is check the "junk" mail folder in their email and they could find the people they needed to do that process.

Third, without a Z visa, this person would not need a reference letter or a release letter because working on an F visa is not legal in the first place. So they don't need those letters unless they were employed on a Z visa.

Fourth, please, just go away, get a normal job like other Chinese people. We don't want any recruiters. We prefer to go directly between teacher and school. We don't need and we don't want recruiters.