Will you be based in Germany? Are you going to join a Eurex member firm as a trader?
If you are trading other people's money in the U.S., then you are subject to U.S. rules. In the first instance, NASD and then rules and regs pertaining to investment companies and investment advisors.
If memory serves me right, as with most continental Europen countries, there are no licensing requirements in Germany. I'll check with a couple of friends in Frankfurt.
If you join a Eurex member frim as a trader, you will have to comply with Eurex requirements. Should you be doing this out of London, you will be additionally subject to licensing by the FSA (UK equivalent of SEC).
cheers