I'm never able to buy the dip. Every time I've tried, the price always goes down immediately afterward. I've just started dollar cost averaging instead. In the long run bitcoin prices will go up, so even if there's a short term dip I'll be good.
21 million. But note that every four years or so the reward to miners for new blocks is cut in half, so the supply of new bitcoins gets exponentially smaller over time. It's estimated the limit of 21 million won't be reached until 2140, but after another three halvings in 13 years 95% of the max will have already been reached. Better buy now, because new bitcoins will become increasingly harder to come by.
The Chinese volume was always massively inflated for a number of reasons:
1) zero fees
2) volume incentives (transferring your own bitcoins back and forth to create empty volume was rewarded)
3) crazy leverages
Chinese authorities very sensibly cracked down on the leverage, and may very well undertake more measures regarding the above points; which is a very good thing.
While well over 95% of volume was Chinese, the estimation is that the Chinese only own about a third of all current bitcoin.