I think German is doing great in this, I'm a new immigrant here. the social stability is high and people in general have lower time preference.
I'd agree your part of value compatibility, however I believe every human shares the same underling value system such as kindness, respect and integration, otherwise we'd be very alien-phobic to see a person in a different color or dressing style or living habit.

Never been to UK or US, can't feel it myself or judge, there's a lot saying the unrest due to too much immigrants. My instincts are the immigration are just the scratch of the problem, with all due respect, it may be very phenomenal but should never be the root cause.

The world has been cycling in terms of order and chaos for thousand years, there's unrest in both immigrant countries and non-immigrant countries, and at the same time there's peace and flourish in both ones. 

For thousand years empires rise and fall, it's the natural cycle. Take an example, not logically related to the root cause to social unrests, the fiat system has been to it's peak and the biggest winners of fiat system ie US and once UK possibly feel the pain. That been said, even if we remove the factor of immigrants in UK, the pain of fiat cultivated habits and people's reliance on the PoS system won't alleviate.
It's weird to say but as part of human nature, it's kind of a destiny of the rise-flourish-falling