As CBG and gasax have said flying in France is mostly hassle free, but this thread was questioning from the States what differences are to be anticipated in Europe. It is better to be aware of the differences than come across them in a foreign language for the first time.
I have been held on the ground for 4 hours because the two hour French lunch meant I could not file until the end of their lunch, and they insisted on 4 hours prior for crossing the border.
I have had to wait for half hour while a security official has been brought from the passenger terminal to the GA terminal so he could wave a metal detector over me and look in my flight bag before I could go out to my aircraft.
I have been unable to leave the apron having just taxied to park under tower control, to find all doors locked, and on trying tower on the radio, finding they are now at lunch.
I have gone to meteo, then tried to reaccess the apron to continue a French domestic flight, only to find the doors are one way , and there is no way to the apron except through the passenger terminal, where a gendarme refused to let me out until he had not only inspected my passport, but also every page of my licence in detail, and queried the date of the medical at length thinking date of issue as date of expiry. On this occasion there was actually no reason to have taken my passport and licence with me, but luckiy I had my flight bag with me. That at least allowed me out onto the tarmac so I could retrieve the aircraft docs he demanded I present for his examination.
All these at different airports. None of which are welcome delays just before a flight.
Others experienced the Dinard problems.
I still fly in France, but expect the unexpected.