>Alot of these people will return home (all over Europe plus Turkey) once in the future, and they will bring home with them - piles of saved Euros, German working ethics and loads of knowledge.

That's what the Germans thought, originally. Turns out to be wrong. If you move to a new place and live there for a few decades, raising your family there, you don't leave unless you don't have any choice. That place is home, especially for your children.

>Europe is trying hard to integrate and mix all the countries and cultures in Europe to the level that would make warfare between their citizens too costly to anyone.

Yes, and it's not working. Even the leaders acknowledge that now. And before they get too comfortable they should remember Yugoslavia tried to do the same thing.