all good points, however is China 'really' slowing down now. They same things were said in 08 when they did actually shutdown smelters (that take days to do and then days to start again).
Even then the effect may will be centralised more in the west than it is in the east.
iron ore is not the only thing China needs.
A lot of this is just investment ripple a big ocean of finance, providing opportunity (my day trader friends love it, as do many here). The same goes from property in that respect, eexpect it takes years noy day/weeks to return the profits we seek.