Spain and France aren't strong enough in the 1790s-1810s to directly challenge Britain outside of Europe and expect to win. The ARW was the straw that broke the camel's back in the case of the French economy, and if that wasn't the reason they went bankrupt in 1789, something else would have done so not too long after. In this time, neither country has the ability to be actively trying to get more colonies, otherwise there is a reasonable chance that at least Spain would have grabbed part of Australia not long after the British (even if, at this point, it was just a flag on the ground and a message to London).
If those two powers are going to challenge Britain, it will be after their finances are in order and maybe after a revolution. So 1825 minimum I think.
Yes to keeping Latin America, no to the Cold War. Cold wars weren't a real concept at this point in time (they only really emerged once war became so destructive as to be counterproductive to the nations involved) - if Spain and Britain don't like each other and there is a clear reason, they will fight about it. And that is a fight that Britain will win.
Who? and why? As of 1780, no-one really had any interest in colonies in China other than the Portuguese who had Macao. Qing policy at the time was also very restrictive to trade, so "spheres of influence" doesn't really apply. China is too big and too powerful for one country to say "this is all subject to me only". I couldn't justify a way for China to become one nation's subject in my TL where colonisation there happens in 1950, there's no way it is going to happen earlier when the tech difference is so much smaller.
- BNC