Although at first glance this appears to be a strange post, I think it shows a degree of foresight and courage to ask those questions in the "lions Den" of PPRUNE. With the wealth of experience on here then it is fair to say that some of our experiences can help someone on that first rung.
OP: As you have an IOT date then you will have been through many interviews, tests and visits. How did you feel when you left these? Were you elated to find out you had passed?
You have a degree but what in what subject? Was the degree a fall-back just in case you didn't get in as pilot or was it a degree to tick a box? You mention it taking years to reach front-line, well it takes 7 years to train as a dentist or vet and at the end you are either staring down gaping mouths or up sheep's backsides! What are your career prospects if you do change tack now?
Life on the UAS: Unsure as to which UAS but from what I saw they all had a good time and bonded well. You will make lifetime friends and they will support you through the hard times in the same way you will support them.
Isolated bases: Going back a few years but it was always the isolated bases that had the best out-of-work life. Most people hung around at weekends and the social life was excellent. I see you are in the South West but I am not sure where. Are there family / partner ties that are making you question life in the grim North East?
IOT: I didn't do IOT but went through the far tougher course at Dartmouth ( :-) ). There were times when I and my course mates questioned why the hell we were doing it but just knuckled down and got on with it; in reality it is only a small part of the whole picture and is designed to make you question what you are doing but there is a light at the end of the tunnel and it all sort of clicks into place once you break free.
I wasn't a pilot but had 16 very happy years in the RN and RAF. My son is a pilot; 22 years old and hooning around in a fast-jet (the envy of all his non-military mates and his extremely proud dad). He has had hold-over postings and enjoyed every minute of them, making very good friends along the way. Some of whom are very senior officers who were more than happy to give him sound advice and guidance along the way.
For you time is short I guess before IOT. Reading between the lines of your post I think you have already made up your mind not to go and are looking for support to justify your decision. A shame really as you have already achieved a lot that others can only dream of and, from personal experience, you may regret not giving it a go.
Good luck whichever way you go.