2) The numbers provided are adjusted for PPP.
4) Whether urban or overall, it illustrates that far poorer people than Americans are able to save money. The savings rates across the country don't differ significantly. India also has a very high savings rate.
5) Yes, and it's still poor by US standards. So was 1950's USA. If 1950's Americans could save (did they), why can't vastly richer 2016 Americans?
6) As I noted, Chinese people save money by reducing consumption.