In regard to the discussion about gas:
Prime minister Luvsannamsrai tells FT that Rio Tinto’s Gobi Desert copper mine is on track
The key being the bit about connecting gas fields which traditionally supplied Europe.
Whilst this is an assumption on my part without proof, I expect that gas and other things (notably oil and coal) supplied to China from Russia will have two fundamental characteristics which differentiate it from the traditional approach.
The currency used will be whatever the two agree on but realistically it'll be Russian or Chinese, it sure won't be any Western currency.
It will not be for sale to others at any price unless the buyer, China, deems it surplus to requirements and chooses to sell in which case it'll likely be offered to "friendly" countries first. In this case see point above regarding acceptable currencies.
The real game here as I see it is a geostrategic and financial one, it's not simply an energy supply arrangement. It's about taking resources off the market, locking them up under long term deals, and removing Western currencies from the equation entirely. That's my interpretation of it at least.