I am only going to address the last point, because I believe is a summary of your whole critique.

> The very idea that everyone experiences the same emotions is itself a cultural byproduct of a culture that often sees itself as the mirror of the world

I was raised by people from different regions, who spoke a common language. When I was a child, we moved to another region that spoke a different language. By that time I had already became bilingual and multicultural.

Then, I learned English. Yeah, not my first language, nor my second.

Eventually, I married a foreigner from a completely different culture to mine. We moved to a third country, then a fourth. We currently live in what is arguably the most cosmopolitan city in the world, with over 50% of foreign-born residents. And no, I have never lived in the US, although I've had coworkers there.

Does this help clarify how much I conflate language and culture, or how much my thinking is "a cultural byproduct of a culture that often sees itself as the mirror of the world "?. Or is it possible that my thinking is shaped precisely by the variety of languages, cultures and nations I've been exposed to?