Well I'm not sure I can of much help with them, although a bit of googling found this which answers your 1st and 3rd questions : http://www.telecompaper.com/news/thames-television-plans-satellitecable-channel-launch--3870
As for Maidstone, I'm fairly certain the channel never came from there. It came from Teddington from launch until 1997 when all of Pearson's operations moved to a new HQ in Stephen Street. The daily studio based programme moved there as did channel playout, where it stayed under various owners until Red Bee took over the contract to play out all of Flextech's channels, whenever that was.
Of course the channel's management might have had offices at Maidstone
As for how many idents were there, I've no idea, and I wouldn't have thought that any record of that would exist anywhere. They had a fair few when I worked on it. I remember seeing a recording session where they filmed some more... some of which were very odd and not used. I have some on a tape somewhere I think