2: Was there a reason that the BBC News / BBC World closing title wasn't played at xx25 during this era in overnights and the sting was played?
I'm not sure, except to say that the overnight bulletins had always ended with a sting as far back as 1998 when they had been introduced. Not sure if the fact that the sting ended with a sustained hold meant that it was a bit easier for BBC World to opt out? If they had used the closing titles it would have had a definite end/opt out point. Maybe it was along the same lines as the start of the bulletin that used a vamp starting with an extended staccato section to facilitate the opt in for BBC World?
3: With regard to WBR was the camera on the London presenter in N9 always meant to be off balance from "normal" camera position for that chair? (If you get my drift)
Yes, it was always like that for World Business Report. Presumably to differentiate it from the news bulletins. Eventually, in August 2001 the N9 set was upgraded to also include a plasma screen on the right side and from then on, WBR was presented from the other side of the desk.
4: What was the shortest countdown ever played out during this era given that 12s is shown in the clip?
Don't know for certain, but pretty short I imagine. I'm sure I remember some on either News 24 or World (once World had introduced a proper countdown instead of the 10-second countdown and symbol they used to use) that were 5 seconds or less.
Long before I even had access to News 24, I'd go to a friend's place and sit in front of the tv and just love watching the 90 second countdown. It was played out quite often during the daytime way back then. In relation to the question Robert has tried to answer I can only guess that during the overnights and because World's countdown was only ever 10 secs initially, that News 24 stacked their adverts as close to 10 secs as they possibly could.