OilCan, you have done what I have striven not to do over the last year or so, started a separate thread re an MAA. Your prerogative of course, but the glaring problem here, IMHO, is not the difficulty of setting up and agreeing the Terms of Reference of such an Agency which will be great, but the overwhelming proof in the various threads on this Forum that the present arrangements have failed, and fatally at that. It’s bust and I believe beyond fixing while the operator is its own regulatory authority. Self regulation, that very British disease, never works as it purports to but ends up covering the backsides of those who fail their customers, clients, users etc. In commerce that can be expensive, in aviation it's a road that you travel at your peril and that of others as well.
The role of an MAA would be to see that UK Military Aircraft are supplied fully airworthy, i.e. in accordance with UK Military Airworthiness Regulations, and remain so. It would be for the MOD to decide which aircraft it wants, which systems they need, and how they should be maintained. If any of those decisions adversely affect airworthiness then the MAA will say NO, as you put it. The emphasis would be on prevention rather than cure which seems to be the way things happen now. If the MOD can, as it has to, involve private commercial bodies in these decisions, then I see no reason why a separate regulatory body should not be involved as well. Personally I am not looking beyond the provision of Military Airworthiness. That is where the problem is and where an alternative solution must be found. That is enough to be going on with. The problems will be great, but the prize would be Airworthy Fleets, well worth the effort surely?