Since there is a 3 % hurdle in the EP election both FDP and AFD Will have seats there. Amy news which group AFD Will join? ECR or EFD?!
1. I expect the AFD to do way better at the EU election next year with them being one of the few options eurosceptic voters have. It wouldn't surprise me if they get a result in the double digits.
2. It isn't clear if there really will be a 3% treshold. In my opinion it is likely that the constitutional court will rule against that treshold.
I haven't read any news regarding your real question.