I think i get it, if there is a possibility to have problems with licence from other Bundesland, what to expect for licence from another country...
There aren't any issues with a license from another Bundesland, I just pointed out that the PPL is administered by each Bundesland (IR and above are handled by the Federal CAA), so some details could be different depending on where you are and who you're talking to.
A Czech PPL is valid in Germany and on German registered aircraft, it's EASA after all (or should I say JAR FCL?). You might need a German language certificate later on if you plan to land at aerodromes that only offer German radio communication according to the AIP. Provided you know the language, that is easy to get and not even linked to your PPL.
PS: Don't be surprised if the Czech have similar requirements like criminal record, etc.
