China is a parasitic economy living on borrowed time. It’s parasitic in the sense that its economy is almost entirely based on foreign trade. When the rest of the world is no longer able (or willing, when countries start setting up protectionist regimes and bolstering their own industries) to buy China’s goods, China will fold like a cheap suitcase, and will return to its normal state of internal disorder and poverty. If China is foolish enough to try the superpower game, it will burn itself out in short order. As for your other worries, well, China’s military prowess is trumped up by people (mostly of the neocon persuasion) who are nostalgic for the old Cold War and would love for us to have a new Cold War with a real enemy (Islamic fundamentalists don’t quite cut it for them).
During the building stage, I think you would have had more of a point. China now has most of our technology, and a domestic economy that can sustain at least some semblance of it’s current stance.
I’m not convinced that if we and every other nation pulled out at this point, China would go back to what it was.
I’m not totally convinced you’re wrong, but have serious doubts.