Don't know about the rest of the points, but I looked into several job opportunities at Berlin, and was shocked by how low their offered salaries were. That was the end of my interest in looking for jobs at Berlin...

I live in Denmark currently, and can attest that to some extent, salaries cannot be compared because of different social structures & expenses. Getting paid 50% of what I used to make in the US did not mean standard of living went to 50%. But, for a comp.engineer, US wins out by a huge margin in terms of money.