sorry, i am not trying to suggest you aren't providing an honest account from your pov. it is more that none of what you report seems to make sense based on BA normal operating procedure.
3. Flight door opened and Captain emerged. Rather than interrupt the demo he went to main door and started fiddling with it himself;
i still have no idea why the captain would come out of the flight deck (was the door closed and then opened up again?) and start touching the door with a view to opening it. this is the cc's responsibility for obvious reasons.