>>25593932
Parts of Central Asia were basically treated like satraps though, weren't they? Given the poor control China had over Tarim, and that it would be more difficult for e.g. the UK to intervene as they did in Iran or Afghanistan, Tarim seems like a good place to just try to vassalize locals without needing a ton of troops. The area also had a history of distinct polities which could make the notion of being largely autonomous vassals more appealing.
>>25593943
China couldn't fuck Russia at that point. Maybe they'd be able to occupy Vladivostok or something for a while but they'd be ultimately incapable of marching west, or at least less able to do that than Russia would be of occupying Beijing, however unlikely that might be. The only real threat would be London and Paris intervening.