Not exactly because that's not from the current edition. The flatbed truck blocking the pedestrian crossing isn't shown any more.
That is from the current online version.
I didn't look at the illustration for box junctions, but isn't only one vehicle in that illustration stopped at a red light? The white van, top right. Its position is legal but foolish because it gives them nowhere to move out of the way legally if another vehicle stops besides them. It's not a great illustration, is it?
Yes, because it illustrrates what you are normally expected to do.
You don't pull up leaving excessive space on the very remote off chance that an emergency vehicle might want to get through.
I'm not sure that has EVER happened to me in 45 years of driving, that I was at the front of the traffic light queue when an emergency vehicle came from behind on blues & twos. I certainly can't remember it happening.
Anyway, can you find any place where it says the white line "is there to indicate the point at which you should stop" as you wrote earlier? It actually says the reverse: it indicates where you MUST stop behind and MUST NOT move forward over. This is similar to the speed limit not being a target: that white line is a movement limit, not a target.
OK, I said "should" rather trhan "must". that doesn't reverse the meaning.
That's debatable, but the space is necessary in order to comply with rule 219 if a blue-light vehicle approaches from behind: "take appropriate action to let it pass, while complying with all traffic signs".
You do not need to "comply with rule 219" until it happens.