In theory Bitcoin does expand the global money supply. It doesn't increase the USD money supply any more than Euros increase the USD money supply but it does increase the overall global money supply. However it is currently a rounding error. Global M2 is on the order of $50 trillion. At ~$5B Bitcoin represents 0.01% of the world's money supply so even if it increased by a factor of 10x in one year it would be essentially nothing. Maybe someday it would have a meaningful effect but right now it is like pouring a bottle of water into the ocean and asking if it increases the amount of water in the ocean.
Yup. But imagine what happens if a tiny bit of that ocean flows into the BTC bottle, that is why China is not needed for 4 digit prices.