The French military corridors are no problem as long as you are not cloud restricted.
In the main they are 800ft to about 2000ft above surface.
You can get a noise certificate free from the CAA which will save you from paying double landing fees at German airports, Augsberg for instance.
A silencer will probably not be necessary to meet the noise
requirements.The certificate will give details of your propellor amongst other information.
The SIA VFR charts and rules pack is the best guide to flying in France, together with the appropriate OACI topos