[germanier]

If you operate an independent Office of a foreign company in Germany (what your suggestion boils down to) you have to abide by almost the same laws that would apply if you had been incorporated in Germany. I assume it's the same in most other countries. Only huge companies can get around this by operating in many different countries and actually having employees in each of those.

[skimpycompiler]

You don't have to. You have an office in Germany, you work for the office in the US. Both companies are entirely unrelated, only thing that bonds them is a contract for doing the work. You are outsourcing the stuff from US company to yourself in Germany.

What US company is selling, or doing, isn't something EU would control.