would the Chinese allow a free unified Korean peninsula?
I don’t think reunification is on the table. My understanding is that North Korea will be helped in becoming something akin to Singapore. That’s what they get if they can come to terms with the US.
President Trump has been pressuring China to use its leverage to bring Kim into contact with reality.
So yes, I believe China will be ok with it. Because Donald the Strong, as the Chinese call our President, said so.
If there are no nukes there, probably yes.
would the Chinese allow a free unified Korean peninsula?
If they wanted to stop things, they could have. Since they allowed (if not encouraged) this, I think the answer is yes.
A developing North Korea is a new market. I would think North Korea would copy the Chinese form of Capitalism.
Since there won't be a free, unified Korean peninsula in our lifetime then I'd say that's a moot point.
The south Korean economy is capable of buying a lot more crap from China than the north Korean one is. And does not require continuous handouts. The guys calling the shots in the PRC may be commie bastards, but I’m pretty sure they can do basic math...