I dont understand how it is that different national authorities have different legislation (if this is so) and / or are seeking to change their own legislation given the intended European harmonisation. Presumably we are very close to having one single European rule, or is there a danger that we will see more national authorities filing exceptions?
They can "file exceptions" all they like but I would imagine they'll go straight into Claude Probst's trashcan.
Equipment requirements will come under EASA when they take over Ops, and I can't see them doing it other than "as appropriate to the route to be flown".
Here's what the Essential Requirements say, and I can't see that getting more than the lightest implementing rules for private flights:
An aircraft must be equipped with all navigation, communication and other equipment
necessary for the intended flight, taking account of air traffic regulations and rules of
the air applicable during any phase of the flight.