Agreed. But to be honest, the US DoT has a vested interest in dealing with each European country separately, as it allows it to use its considerable negotiating weight more efficiently than if faced with the EU as a whole. Then again, that's largely due to each EU member-State not surrendering their negotiating powers to the European Commission.
Good point on ATC and certification issues. I would go further: I would like to see the day when there are no more JAA, FAA, Transport Canada, CASA etc. licences but only
ICAO flight crew licences. After all, aircraft don't fly any differently depending on which hemisphere they happen to be in! But somehow I don't think that will happen in my lifetime...
Cheers