I can't think of an instance of an economy "collapsing under its own weight." China might run into issues with currency manipulation, but aside from that they will be most stable so long as they keep growing at a fast clip. The problems will start to appear when growth slows or stalls, and people no longer see their lives or children's lives getting better (e.g. the Arab Spring)

There's the signs of an early housing crisis (i.e lots of apartments being built, but nobody's buying). Entires cities stands empty, without occupation. That seems a bit like an economy that's heaving trouble maintaining itself.

Ah so you're saying the government pumping up economic growth artificially won't be able to continue indefinitely. I'd agree: organic economic growth can't cause economic collapse (unless there are serious infrastructure issues) but artificial growth certainly can.