Of the remaining ones I’d say Fedora is probably the safest bet. Not as cutting edge as the other two, but well engineered and stable.
Rolling releases like Tumbleweed and Endeavour can be more interesting and partifularly good for gaming because they always have the newest stuff and patches and performance improvements. Which can also bite you a bit in the back though if you have an Nvidia graphics card. Nvidia doesn’t play too well with open source and they don’t put a lot of effort into it, so the newest versions of their drivers occasionally break or do stupid stuff. Which isn’t a big deal if you have a system that can rollback (tumbleweed can, dunno about endeavour) but might be a bit annoying sometimes
They do. The official government line currently is that they have no need to formally declare independence (which might trigger a Chinese invasion) because they already are an independent country by most meaningful measures (which is true of course)
That used to be the official position decades ago. But apart from a few old nationalistic farts maybe, nobody on Taiwan really holds that position anymore.