As far as I know the current limit in France is 10J, say 7 fpe, so you will have a legal issue when you want to attend a shoot now. For the worlds, I always was in the assumption that the organizing country would arrange the proper license/aggreement for 12fpe/16J to enter the country, like Italy last year.
Germany also has a limit, 7.5J /5fpe , but the Germans have arranged the use of 12fpe/16J for the worlds in 2013. Our FT club arranged a special permit with the German police for attending German FT shoots trough the whole year, it takes some effort but it is obliged in order to enter Germany.
So you only need to take care of the countries you will cross, if you go by car. Belgium and Holland are no problem at all, no limit on airguns, even if they are 500fpe....strange, but true.