Do you have a German passport? My understanding is dual nationality is only allowed with EU countries, not 3rd countries...
No. I can only obtain this after 8 years of continuous living. I can start the application after 7 though. I have been here 6.5. And you are correct about dual-nationality; you are expected to give up other passports. There are exceptions to this law for some specific impractical, difficulty or political/religious reasons. I can’t recall what these are.