If the regime in Beijing feels itself to be threatened, it will retaliate with nuclear weapons, same as Putin, same as the US.

That one is up in the air, remember the Soviet Union dissolved but with no nukes as they had a way out. America has a history of winning but letting all the people within the regime off the hook or even continue working (Japan after WW2) so China may not go nuclear so long as they know they have an out and a couple of fall guys ready.

And it won't stay local because of Japan in the area, they know if Taiwan falls they're next so the US would be forced to act to defend Japan

The Chinese have relatively low corruption, a very competent state, amazing economic growth

Depends on your definition of corruption, as I said, they have the same problem that the Soviet Union had, the ones lower on the pecking order are reluctant to inform of bad news lest they be next on the chopping block, and this is China, people disappear and in a conflict those kinds of communication delays may mean reinforcements are too late and the enemy already recovered.

And a lot of that growth is artificial, they control their currency to the point that they on purpose make it worth less so that they can fix prices