I live in Normandy and have never had any problems with the Police, in fact I never see them. As with most places you will attract attention if you ride like a pillock and/or ride too fast. If you get stopped it will be because of the previous two reasons or they are conducting road checks for drink...

Tweaked over the years but now just what I need:
Bike tool kit
Multi-tool with numerous different screw driver/socket/allen heads
Cable ties
Gaffer tape
Small torch
Spare fuses + bulbs

No puncture repair kit as I put Autoseal in the tyres.