IO540 You are so right, the problem with interpretation of part M is political. LAEs have studied long & hard to get their licences, and are going to be well fed up if lots of owners go DIY. Their attitude will understandably be "either I do the lot or none at all, take it or leave it!"
There is a middle way in my opinion, but it's going to need a lot of trust to get it to happen.
As regards your TB20, you are probably familiar with the EADS SOCATA website
www.socata.eads.net this gives a list of maintenance manuals under the GA section. The manuals are published in French & English, and the French ones will have a GSAC approved type-specific maintenance programme. I doubt that the English version will have that programme, because until part M came along there was no need. US registered aircraft used FAA procedures, and UK used LAMS (now rebranded as LAMP) Both LAMS & LAMP are generic programmes, which require an engineer to interpret using his skills and experience to do as much or as little work as seems necessary. The type-specific programmes however need no interpretation, since they say what has to be done and when to do it. So a competant mechanic can achieve full & safe servicing, which is the key to pilot/owner maintenance. You could obtain the French maintenance manual for your TB20, and submit the French type-specific maintenance programme to the CAA for approval if you wanted to put your aircraft on the G register. French is an official EU language so the CAA should accept it. You might get someone to do an English translation for a small sum & a few beers, but only the French language version would be legal. But your aircraft is considerably more sophisticated than my simple ATL, so there will be a number of servicing procedures in the annual check which do not fall under the appendix VIII list of pilot/owner permitted maintenance. My guess is unless you enjoy very good relations with your local engineers, they are likely to tell you to get lost if you ask them to do those tasks only and not the whole annual.
As regards ARC renewal when not in a controlled environment. EASA CRD to NPA 2007-08 brought in the owners choice of having the review done by the NAA, or by any CAMO with part I privileges.
The French GSAC published a useful guide to implementation of part M on their website at the end of 2007, but it has been withdrawn, probably because already out of date due constant moving of goalposts!