Homogeneous - but I get your point. But that's something a cohesive society aims for, not fracturing like happening in the US. The point of a society is cooperation.
Not sure number 2 is a real issue or problem in free societies or "most other countries", although some media and social sources with an agenda might try and convince you it is to distract you from other bigger issues they'd rather you not investigate.
I don't agree we prefer our own problems because they are familiar to us. We have a global flow of people, the very existence and foundation of the US is this, which implies people want a better life, not acceptance. Protests, emigration, changes of attitudes as a society to thinks like slavery, womens rights etc all point to an evolution of mindsets.
Every country evolves, people evolve.
Countries typically that were at war are now cooperating. Look at the US and Russia relationship now vs cold war, but also look at how Europe has healed from wars by change.