The USA being wealthy seems like a weird idea from a lot of the USA territory.

See : MS, LA, AL and consort.

At some point you can’t ignore the division between the map and the territory.

At best the USA is a country, with rich people in it.

As opposed to say, Switzerland, a rich country.

And number 2 and 3: don’t underestimate the power of exported American culture via the media. There’s a clear trend (in English speaking countries at least) that the culture is becoming more and more Americanised, especially among youth. Non English speaking countries tend to resist it more but the influence is still there.