Jacko
1/ Range, endurance, capability, capacity, comfort, future growth, self deploy, etc. Think you answered the question yourself in #9
2/ Is true of almost any asset we have.
I would say it is a niche capability, an extremely useful one which 51is very good at, but it is only as a force multiplier (or what ever it is called now).
Because it's something we do very, very well, - such that R1s and PR9s have often been the first UK capabilities that coalition commanders have asked for - it is a capability that gives us greater influence in coalition ops.
Sounds like something I would read in the RAF News,
PR spin.
Why should we maintain more capacity than we require when we are so desperate for cash throughout the Forces, we are not here to bolster other countries lack of capability.
3/ True 707 is out of production, but it will be supported for a good few years yet. I wouldn't advocate buying more 707's but how long do we intend to operate the E-3D for, if some were converted then we would retain much of the airframe comonality keeping support cost down, rather than introducing another type.