I know that working in France maybe a little bit more difficult compared to working either UK or USA. One US trained physio I met there before moved to France to settle with her new family, she speaks quite good French. She has been in France for 2 years but she was still not allowed to practice PT in the hospital or even private practive because she lacks some criteria / qualifications required to be given permission/license to practice.
I hope you find someone here that can give you more insight. Goodluck to your plans.
Bon courage!