It amazes me the limited memory span of punters on here. For example why don't QANTAS serve Manchester with a B744 onwards from Heathrow. They used to but found a more profitable way of doing it. They code share on the BA shuttle so they still get the same passengers but don't have to fly a Jumbo on a short haul route to get them !
It's the same reason BA serve so few routes in Asia, they are served onwards from the hubs of their Oneworld partner airlines like JAL and QANTAS.
For the multi landing questions of London flights routing via MAN, that would be commercial suicide as the London market is highly competitive and you want to run a flight that isn't NON STOP and takes over an hour more????? Really?
As for BLK-LCY, that would stand less chance than the recently axed NCL and BHD let's be honest.