Chinese people often the most anti-foreigners and Indonesians the nicest
I can't comment on the Indonesians or Japanese very much, but one of my best friends from the time I did an Erasmus scholarship in Italy was a Filipino girl who was very outgoing, very non-judgemental and friendly with everybody, and if I'm not mistaken, just like Indonesians, Filipinos are a related Austronesian people, (though they received a lot more Spanish and American influence from the time they were colonized by those 2 Imperial powers) so maybe Austronesians in general tend to be friendly?
Obviously no stereotype holds true in too many cases, and I really should shut up about this given that my sample size is one person, and she was also an atheist, which is very atypical in the Philippines...
However, the part I could chime in on is "anti-foreigner" Chinese, as I had three mainland Chinese friends and interacted with a lot more on the internet, and... eh, I'd kinda agree with you with some caveats. Chinese tend to be at least patriotic if not outright nationalistic even if they are leftists, (partly a product of their culture being ancient and their empire having been the wealthiest on Earth for about half of recorded human history and very culturally prolific, but far more so I think a product of their country having been very poor in the past 2 centuries, carved up and raided several times by European colonial powers and Japan since the first Opium wars, and Maoist propaganda, so a lot of Chinese grew up with the idea that, except perhaps Russia, China has no friends in the world and most foreign powers wish to exploit it when it is weak and hate/envy it when it is strong) BUT almost none of them in my experience were racists and if they realize that you are foreigner who respects/knows more about their culture, traditional arts, language or history than they expect from a foreigner, they will often warm up to you and become very friendly.
Basically, at least in my experience, most Chinese are nice and do not hate foreigners, but a lot of them will assume foreigners hate/look down on them, (which is not that wild of an assumption given for example the rising anti-Asian hate crimes in the US) so they can come across as anti-foreigner. And, well, if you mention Taiwan or the South China Sea you'll most likely get into an argument just as much as if you bring up Okinawan independence to most Japanese or tell them that the Kuril Islands and Sakhalin are rightfully Russian - East Asians in general tend to be very nationalistic when it comes to territorial claims, at least in my experience.
If we're talking living there I hear mainland China actually has extremely low criminality (I've seen vids from female expats living there, a Slovak girl and an Australian one, talking about how it's 100% safe for them to go visit a night market at 2 am in the morning in Pijamas in cities like Shenzhen or Hangzhou and never get assaulted or robbed), has very uniquely-designed modern cities with excellent public transport, infrastructure, large parks, green spaces, theatres or public cultural centres, some of them even with historic centres, which is quite rare outside Europe, but I've seen even American-born Chinese say they wouldn't be able to lead a very dignified existence in China, as, well, a lot of the crucial everyday apps that you have to use these days need you to read Mandarin quite well, not just speak it...
Taiwan is definitely much more liberal (I think they're the only country in Asia to have officially legalized gay marriage), and probably more English-language friendly (at least there is Google Maps there if nothing else...), so I'd probably agree with your choice that it's the easiest to adapt in/friendliest for a European or Western migrant who doesn't speak the local language.