Re: RAF transfer
I don't think there is a strict set of rules on this one.
Known plenty of Ex RN and AAC mates who have transferred. For the officers, if they have been experienced aircrew then, many of them have gone merely to collect uniform and are Flt Lt XYZ That day.
Others have done the short course (was called SERE, no idea what it's called these days) I suspect that doing this course is merely a mechanism to let some of the previous experience rub off on the other cadets. (Pure conjecture)
It does seem though that the more qualified/experienced you are the more you will be able to bargain your way out of doing the SERE thing and just going to Cranditz to collect your uniform.
What are you qualified to do?