ATG
Why do the MAA get to make that operational decision?
They don't, the local commander does, but has to justify it later. That holds true whether the MAA is inside or outside of the MOD, ie it holds true now! The point about airworthiness provision is that it is done before you get the aircraft in the first place, let alone go to war in. It is that first phase that has been so neglected and led to fiascos like the Nimrod saga. It wasn't grounded because 14 people died in it, it was grounded because it was going to cost a fortune to get it put right. If it had been done properly in the first place, 14 people live and MRA4 would be in service. That is what an independent MAA would ensure, that it gets done properly from the start. Legacy aircraft are of course a problem, part of the mountain of problems that the MAA have to deal with. They can't begin to do that if the same pressures that got us compromised Nimrods, Chinooks, Hercules etc can do so again and again.
As to it being all civilian, I don't see why it should be. If RAF Air Traffickers can serve alongside civilian ones, I don't see why the same thing can't happen in the MAA and MAAIB. The organisations might be civilian, it doesn't mean all their staff have to be!
Tourist, whatever definitions you quote (and believe me they will change as quickly as the title does of the issuing authority), Military Flight Safety is a Force Preserver. Of course going to War isn't, and is the ultimate purpose of the Armed Forces. Who is saying otherwise? Certainly not me!