I'm not from the US and I've never lived there, but from what you're describing (except point 4) it seems like stress is one of the fundamental values in the US society. Stuff like not having public healthcare, exorbitant college costs, being fired at any moment, etc. It seems like kids are taught that early on with the stuff you're mentioning through the imposition of cultural values, rules, etc.

I'm from Europe but I grew up and have lived in different cultures/countries which have a much more relaxed attitude towards life. Reading your comment actually made me anxious.