Personally I would employ an accountant anyway as they can often save you money (even taking into account their fee) by advising on the best way to set things up to mininise your taxes, but up to you.
In your situation I would get an accountant on board who specialises in tax affairs for Sweden and France and ask them how best to manage your affairs so that you meet the requirements of both countries and are tax efficient.
Personally I would employ an accountant anyway as they can often save you money (even taking into account their fee) by advising on the best way to set things up to mininise your taxes, but up to you.