The primary reason most Americans would not care comes down to policy. There are thousands of things that we refuse to export to China, and adding a few computers to the list wouldn't raise any eyebrows. Both major political parties are strategically invested in Taiwan, so there is a bipartisan motivation to pass tough-on-China policies. It's definitely arbitrary, but not unwarranted; China invoked this through territorial aggression.
The rest of your examples would probably make even the least-patriotic Americans laugh. The right to self-determination is not an invitation to Maoist-Famine your entire population. There are humanitarian (as well as territorial and political) implications to a nation's actions, especially when it takes up arms against it citizens or defends a mistake of international concern. Very few remaining Americans share your anti-globalist mindset - tragically, the few who do are obsessed with American exceptionalism all the same.
I hope that could help. Words can't describe how nuanced the American national sentiment is, there are layers of secularism and faux-support that are overriden by completely different ideals. It's not much different from most places in the end though, I'd imagine.