Mr Read - I am afraid that yes, it does sound like ramblings!!!
I am sure that whatever you saw looked quite hairy to you, but please remember that your angle of view will have distorted the real picture. It is incredibly hard to judge how close two aircraft are when viewed from below, especially if the aircraft are at altitude.
Expressions like "going up the tailpipe of..." do not help either - its the kind of language used by sensationalist journalists.
Please rest assured that the aircarft in the skies above your head, whether you are in Dulwich or Biggin Hill are safely controlled by experienced Radar controllers, and flown by professional pilots, not boy racers!
Hope this helps!
Mr Chips