> Do they have a track record of making trusted CAs misissue certificates?

Probably not. Any CA missisuing certs intentionally (whether by government coercion or not) probably wouldn't remain trusted for long. So if the Chinese government is doing something like that, the public is certainly not aware of it, else there wouldn't be any Chinese CAs left that are still trusted.

That's the beauty of the trust store. The PKI might be a fucked up solution to our trust problem on the internet, but it puts enough pressure against governments to throw them away.