Wow - well this thread has exploded - I apologise I was not available last night to reply to any of these posts regarding my 'incident' at Nuneaton. There are too many responses for me to quote and reply to each, but hopefully I can reply to the general sentiment.
First of all, I appreciate all of your replies and opinions, even those that cast me as a difficult passenger. I certainly agree that on this specific occasion that I was being difficult, however please put yourself in my shoes: I travel almost exclusively with large and heavy bags, being a seafarer, and almost all of the journeys I undertake with these bags are at least 6 hours long, usually with at least 4 changes. After each one of these journeys I am left restless, with back pain from the heavy load, and I do not at all think it is unreasonable to want to plop my bags down at the side of the platform (least likely to obstruct anyone walking past), and then stretch my legs a little bit after having been sat down for two to three hours. This is most certainly the first time I have been 'difficult' in regard to this issue, and it was only through sheer frustration of what seems to be (to me) a lack of common sense by members of the public and railway staff.
I'd like to reiterate that I was the only person on Nuneaton platform three, besides the dispatcher, and I was stood less than 5 metres from my bags, gently pacing to keep warm. If I had been the dispatcher, in my mind, all it took was one quick glance over to me (again, the only person in the vicinity of the bags or even on the 11-coach platform), and had she done this, I would have quickly taken my headphones off, and explained to her that the luggage was mine. However, her reaction was almost the complete opposite of what I personally (clearly everyone is different) would have done, and I truly struggled to understand how the most sensible course of action in her mind was to start the reporting process upwards, to her manager and then presumably to the BTP, when there was one individual on the entire platform who was extremely nearby and could've been asked immediately whether the bags were his or not. She did not at any point even make eye contact with me, and I certainly was not ignoring her presence. I am never out of sight of my bags, or even far away from them. I could've reached my bags within 3 seconds of movement, and in fact I did when my train arrived.
In all the other incidents I described in the OP, at no point was I being difficult as I was at Nuneaton, and at no point were my bags far away from me either, and each time I immediately confessed ownership of the bags to whoever was trying to enquire about them. In fact, in several incidents, my feet were literally centimeters from the side of the bags at which point people started enquiring if they were 'left luggage'. I understand my bags are perhaps a bit bigger and heavier than people may be used to - but still, it is not uncommon to see several large rucksacks on a train, in my view. It is extremely uncommon for such things to be a threat.
After weeks at sea, and faced with incredibly long and arduous train journeys with large luggage, it can become easy to get irritated at people constantly poking you and enquiring about what is an entirely innocent and normal and expected behaviour: having luggage on public transport.
In retrospect, I did not make the dispatcher's life at Nuneaton easy; however it does not make my life easy to be continually prodded about my bag full of waterproof clothes and underwear on a regular basis - and I just wish some common sense could be applied. I do accept that it is not the dispatchers fault that we live in the world we live in, and should I see her again, I would apologise to her.
I hope that those who cast doubt on my sincerity and behaviour can perhaps see it somewhat more from my side - just because I have a large bag does not mean I am a terrorist, and if someone had enquired about my bag (which was clearly mine at Nuneaton, in my opinion, again only person etc), I would have been happy to help - instead of a passive aggressive reaction which in turn evoked a passive aggressive reaction from me.