So there masterplan is to invest millions of dollars into a mining farm, collaborate with other farms that have done the same, destroy bitcoin and lose everything?/ sounds like a solid business model...
No. But they do have different interests than regular users like you and me. For instance, they need higher fees, not only now, but especially in the far future when block rewards get much lower.
While as a user I like low fees and large blocks, so my transactions are confirmed faster, the miners benefit from small full blocks, as users have to compete by increasing fees.
If you are really concerned about chinese bitcoin miners and china's greed in general, you can try to stop using chinese made stuff.
That won't change the fact that miners go where power is cheapest.
I'm curious now what electricity costs in China.
First hit on Google:

I'd say India has potential here. Or any location with a very big hydro power lake with very cheap electricity in a remote location.
Wouldn't this be a serious possibility if the majority of miners agrees to do so? What stops them from saying: "from now on, the first 1 million bitcoins mined will be added to miners fees in the next 100,000 blocks?
There's another downside of it. Chinese gov could easily take control over (vast) majority of hashing power (or shut just shut it down) if they only wanted to for whatever reason. It would require minor operations and, unlike western countries, they wouldn't even have to justify it (search for legal grounds etc).
Say 75% of mining power is gone tomorrow. That means blocks take 40 minutes on average, after a while difficulty goes down, and all goes back to normal. Nothing lost there!
I would more worry about China disconnecting the internet for a while. When it comes back online, they have the longest chain and all transactions confirmed outside of China in that time are gone.