1) No. Has to be a UK issued PPL, and it's only valid in UK airspace as it's not an ICAO compliant instrument rating and therefore only has national scope. What it does do however is allow you to fly VFR on top in France, a privilege conferred by the standard French PPL.
2) Technically yes, but it's a bit of a pain tranferring records between schools. You can take the exams at most flying schools.
3) Good question. It would seem sensible to take the exams in the country in which you intend to do the flying though. The content will be consistent with said country.