Why not ask the Luftfahrtbundesamt (LBA) about this? I did my exams for the CPL-IFR in English.
I think you might hit a problem with the radio license, since the BZF (Beschrankte Funksprechzeugnis or restricted radio license) requires knowledge of basic German. There you have to do a practical test with the Post and Telegraph Authority in German.
In any case, you may find it very difficult to get very far in obtaining a license without the help of a school. Otherwise it can be very difficult to get test dates. Well, that was my experience.
For a PPL you might find it best to join a local flying club.
Good luck, in any case.