I agree with some of your post but I don't believe there is any love lost between the movers and shakers in the BGA and the VGSs. To help with the instructor problem the BGA could come up with a bridging scheme between a A1/A2 Cat VGS instructor to become a 1/2 or Ass Cat BGA instructor, that should be relatively easy and just involve effectively 'differences training' and an assessment. I agree that for Full Cat BGA then the whole training process as for any BGA Ass Cat should be followed.
If there was a will there would be a way. For the BGA this would be an incredible injection of youth into the organisation (that tends to be a bunch of blokes at most BGA clubs I've been to) and for the Air Cadet gliding it would dig them out of a huge hole and free them from the ridiculous over-engineering and regulatory shackles of MAA land.
On that last point, if I had a fleet of 5 Grob 115E aircraft at a civvy flying club I would expect to see 5 aircraft available on the line (maybe 4 when annuals are due), however, put a roundel on it and apply MAA CAMO to it and then you are lucky to see 2 aircraft. We've got it so badly wrong. If the civvy clubs operating similar aircraft had a much higher fatal accident rate due to tech issues then I would agree to this over-engineering - but they don't! MAA regs were written for high performance war fighting jets and helos - you couldn't get any further away with a Grob 115E, a Grob 109 or a Grob Acro...
The B Word