As has been stated the CAA are/will be the 'competent' authority in the UK and have been interpreting the proposed EASA rules with gold plating. From my knowledge of how the French currently do their maintenance I can't believe that they will accept the kind of rules that the CAA are trying implement in the UK.
And as for owners doing their own maintenance this may be true but how many would want to and how many would you feel happy to see do the work?
Ultimately a MO will have to sign-off the ARC to say that the work done, modifications, fitted equipment, ADs and etc are satisfactory. Would you be happy to let any Tom, Dick and Harry do work on your aeroplane and sign for it?
If you work for a M3 organisation you must know that even as things stand there is an awful lot of research and paperwork to do when it comes to applying for an ARC or CofA (appendix 2). I don't see that the proposed parts F & G do anything more than what's being done today except they involve a lot more red tape and expense for the MOs.