About the PBOC i am not 100% sure Bitcoin is not in their best interests. And I would guess they are also not sure. The macroeconomic implications of Bitcoin are so complex that I don't think no parties really know. And that's why no government has made any extreme move about it.
Bitcoin is a means to subvert PBOC policy so it is hard to see how they can be in favor of it. Wu will be a tool of PRC policy when the Central Committee decides it has a Bitcoin policy. China is a communist dictatorship.
If any government entity could control Bitcoin, they could use it to strengthen their exchange rates and weaken others, say the USD for example. It seems fairly obvious that the Chinese government is subsidizing certain miners with free electricity from hydro dams for mining, etc.
Bitcoin can be used for capital flight out of China, but it can also be used to flee other currencies and pump money into China. Isn't that net effect of the block rewards when they're mined in China and sold for USD?