In reply to Bruce Hooker:There is the usual agreement for working out residency for days spent in the country, BUT this is trumped by the rule between France and the UK as to where your children go to school. So if you spend less than 180 days in France but your children school in france, you are still french resident for tax purposes.
Death duties I am not sure. Inheritance law in France is changing for expats I think that have not got French citizenship. THey are looking at UK expats being able to do inheritance the same as UK law ie you can choose who can inherit, rather than French law where there are rules of who inherits wether you want them to or not.
I hear that France is trying to get TAX on monies moved out of France that will no longer be subject to French tax. This does not matter if your moving it to example the UK but your stying in france, or your moving it to the UK as you are also moving to the UK. There is quiet exodus at the moment from France to the UK because of the tax and also due to burocracy restraints that limit the ability to do business. This is an exodus of French, not just expats going home.
Personally I would suggest going to someone for advice that knows the 2 systems well. There are a few out there, they usually advertise on expat forums.