Long post, beautifully laid out and written. 
After the ITV doc earlier in the year I listened to some of the other docs (if you can call them that). I thought the NOWTV doc was interesting in that it contained some new characters eg James Richard, Anthony Arlidge and Justice Henriques to name but a few.
I believe James Richard house shared with Julie and therefore I assume met with Bamber on occasions. I thought he came over well and no doubt impressed the jury and trial judge with his claim that Bamber told him he hated his parents. Apparently upon cross examination he said he recalled the comment as it was said with such vehemence.
I think PC Saxby remained in the patrol car.
Yes the sticky silencer and hair are interesting. I will have to have another look at the statements and see what was said at the time. The accounts seem to vary somewhat.
As you said the pathologist was notable by his absense as was Sheila's psychiatrist.
My issue with James Richards is that he was supposed to be a witness for the prosecution, and maybe I am being old-fashioned, but I think at least in public he should be careful to ensure he is presented in that way, not as a 'friend of Julie Mugford'. I appreciate he shared digs with her, or something like that, but if he is a friend of Julie Mugford, then that makes him look partisan, and implies he is her spokesman and that his involvement in the documentary is to stick up for her. To me, there is just something about it that doesn't sit right.
I forgot to mention the appearance of the appeal judge, but hasn't he retired? I think that should have been made clear. A lot of viewers will have come away with the mistaken impression that he was giving the view of the judiciary. The 2002 appeal judgment was flawed and that view should have been covered, but the scope of the documentary was too wide and they were trying to hit too many topics.
'PC Saxby remained in the patrol car' - that may well be, but you underestimate the verbal agility of Christopher Bews. He is unmatched.
My pet theory about the silencer is, briefly, that at least two of them were examined by the FSS, and one was returned to the Eatons after undergoing chemical treatment for fingerprinting purposes. David Boutflour has then handled this, or seen it, and confused one with the other in his own mind. On the other hand, I accept that it is possible a guilty Jeremy would miss the 'stickiness', etc., of the silencer if he was wearing gloves, and he could also miss a hair.
Yet then you have to ask yourself this: How and in what way and to what extent did he clean the silencer, if at all? If we're saying he didn't clean it because all he was doing was moving it out of the way so that it would not be found, you then have to ask:
(i). Would Jeremy be that stupid in assuming that the police would not search the place in the house dedicated to the storage of firearms and paraphernalia? He is supposed to have planned this.
(ii). Why wouldn't Jeremy just take the silencer away with him? Even if it's absence would be noticed and seen as suspicious, he would never have been convicted on that basis.
(iii). Why didn't Jeremy return to clean the silencer properly? Why did he allow the relatives keys to the house instead?
(iv). If Jeremy took himself and the silencer to the gun cupboard, why wasn't blood found on the floor of the back corridor, Nevill's den and in the gun cupboard itself?
I could go on with the problems. Really, Jeremy's actions don't make a lot of sense if we accept the official narrative. It's a bit of paradox to say that Jeremy is cold and calculating enough to stage a phone call and put on an act with the police, relatives and at the funeral and in other respects, but at the same time, he would not take care of incriminating evidence. Maybe he was just reckless and arrogant and thought he had got away with it? But this is looking at things backwards. At the point he could have disposed of the silencer, he did not know that he had got away with it. I also have issues with the blood patterning found within the silencer. There's also the problem with the drawback theory that the silencer evidence depends on. And there's the questions about the chain-of-custody of the silencer.
I was a bit harsh in my post in regard to Barbara Wilson. I expressed it clumsily. I said her evidence seemed pointless, but that's not correct because she did report her telephone conversation with Nevill. I suppose I have a prejudice about her because she seems like a typical gossipy village woman with some sort of grudge against Jeremy, but she is allowed to give her impressions of the people involved, etc; and, to be fair, it may well be that she had more to say that was edited out but if included would make her seem more balanced in her views about Jeremy.