I flew Lufthansa from Dulles to Frankfurt a month ago. The biggest problem was a 8kg carryon weight limit. I had a laptop and several cameras with me. I had packed everything I could in my check bag. Finally, I was allowed to board with 13kg of carryon baggage. I got the superTSA treatment. I got everything but a proctology exam from TSA. Gunpowder swab testing too. Boy was I pissed. No other problems on the flight. Germany arrival was normal, nothing happened. Lufthansa knew I had a drone (Mavik Pro) with me from the carryon problem.
You are supposed to have German flight insurance to fly in Germany, yet you cannot get it without a fixed address in Germany. Germany requires the metal ID tags which I expected and had. I was able to DL and install the DHL(German FAA) software program on my Android Phone but not on my iPad tablet. The app worked better than b4ufly. No problems flying near a military base as I was just outside the no-fly limit shown on the software. I was not hassled by anyone in Germany and was able to enjoy flying and taking video as I wished. I was always below the 100m altitude limit.
Returning to the US was again a hassle with TSA goons in Germany. Again the pat down and cavity search. I am getting really tired of this. I have a 107 license, a handgun license and ham radio license. Does that flag me? Anyway, I really bitched about this as this was the fourth pat down in a row. Again the check included gunpowder swab. They kept saying that this was random. I say BS. I did not have the Lufthansa 8kg carryon limit in Germany. I just checked in without any problem and they did not even check the weight of the carryon. After the fiasco with TSA, I was pretty pissed until I found out that Lufthansa had upgraded me to Biz class due to a change of equipment. Thank you Lufthansa, you have one great airline, you rock.
Bottom line no problems traveling to and from Germany with a Mavic Pro multi-rotor. Your mileage may vary. I hope that you have pleasant Europe trips.