[rewboss]

To become an EU citizen, you have to become a citizen of one of the EU member states. Laws vary from country to country, but generally you have to live there legally for a certain period of time and jump through all sorts of bureaucratic hoops. It helps if you marry a native.

Becoming a German citizen means giving up your US citizenship, since Germany does not recognise dual nationality. Most other countries will allow you to keep your US citizenship -- I'd definitely recommend hanging on to your US citizenship.

I have no idea how many US ex-pats do TEFL in Germany, but there are quite a few. Most of them are in the old US zone (i.e. most of southern Germany): ex-military personnel who settled here.