I suspect what Xi wants is N. Korea minus a few nuke and missiles. China wants it to remain pro-China. Xi wants Kim on a shorter leash. NK is theirs as far as they are concerned. I don’t think China wants full denuclearization, either. They don’t want any dramatic change. They do not want N. Korea to completely break the status quo.
I agree. This is high stakes for the Chinese communist regime.
North Korea is China’s only military ally, and basically a vassal state - it could also be a giant vulnerability, if it opened to the West, with its long border.
China is going to try to keep tight control.
All you say, but...
China (and Russia too, somewhat) wants to develop and use NK’s all-weather ports.
Needs US approval because most of the goods that go through would be US-bound, or from US. Also needs Japanese acquiesence.