@Nanja 

I assume not  as you need a European passport or Identity card (Even if the rule says country of residence counts and you have a proof that you are actual live in Germany:/)  and note with Interrail you could only leave/enter Germany once as Germany would be your Homecountry of the pass :/ 

With Eurail you can travel complete free :) 

Seewulf is correct indeed! 

I have both EU and USA passport and both USA driver’s license with USA street address and a EU address inside the  “address card”.

In such case the EU/Inter Rail rules allow using Interrail and EuRail at will.

It is somewhat similar to your case. In addition to that, train conductors are not passport - experts from the police. If you would buy the Interrail pass, that would raise far more questions from them and bring you more inconvenience, than EuRail.

There is one huge incentive NOT use the Interrail at all: you are allowed only limited journeys in your “home” country (i.e. Germany), which has one of the most expensive regular trariff as well.

Holders of EuRail are not affected by this limitation. So the best solution for people who are eligible for both: buy always EuRail.