ICBM,
My thoughts are that over water training is all well and good for A-A but not much else. I am sure that the counter point is that one can pickle off a PW4 over water and let it fend for itself much as you could overland.
I have spent many happy hours in the 323s and 613s (the ones off Leuchars...hazy memory) and got a lot out of it as an AD chap. As a mud I thought it a complete waste of my time to be honest.
You are completely right about the ability to go to places and use AAR. I just remember seeing the sums for use of the aeroplane when I was involved more intimately involved in the project and thinking that someone had left transit time out of the equation. In short a mountain and Mohammed situation.
It remains, despite your valid points, my opinion that our Maritime Strike fighter would be better off based somewhere that made sense to train for its core task. Lossie made perfect sense, Mawgan or Yeovilton made perfect sense. I see no added value in Marham, just transit up and down the North Sea to somewhere useful.