Hey MDark - I moved my S4 from the states (direct flight - 1 day) to Ireland and know another person who moved their Dark 600 here (ship - stupid 4 month jobby).
It really depends on how long you are going to be in France as to what you might want to do. Maybe you want to buy a bike in France from a large dealer with a guaranteed minimum buy back amount. That will probably cost you as much as shipping both ways - plus the insurance you are probably going to have is GreenCard insurance which is about 3K a year for comp cover. So if you buy a bike in france - ride it for two years and sell it - you will probably end up spending less money than if you ship your bike both ways plus pay for your greencard insurance. Plus they could end up sticking you for VAT on the bike if you plan on having it there for over a year. I don't know the laws in France but start checking it out. You should be able to call the embassy to get this (and liscensing and insurance) info.
Another option would be selling your baby in the states - buying a US regulation Monster in Europe (probably have to be from Italy) then bring the bike back with you when you leave. If you have it for long enough in Europe, you probably won't have to pay the import duty when you bring it back to the states.
As far as regulations go - I wouldn't worry too much about mods. All standard monsters meet the general requirements (except that Cali Canister) - I mean - how many monster owners do you know that have regulation pipes on their bikes in any country?
As far as the kmh / miles diff - you probably won't have any problems with that - they almost definitely won't make you change your clocks if you are "visiting" vs moving permanently.
If you have any detailed questions - you can post me off line and I can try to answer them. I won't be able to answer anything re: france specifically, but can help you out with some other details.
BTW - you should probably change the title of the post - I only accidentally read it. You will probably get more replies if you do.
