Last Saturday, I was sitting in 1C of a BACX 146 (dear old MIMA still plying her trade up to the IOM) and was looking at the door in question during boarding and at close of the flight.
I was amazed (not for the first time) at the metalwork and was wondering who won the competition for designing it ...
The problem of reinforcing the door and yet allowing ventilation in a suitable manner is difficult and I'm sure that, one day, someone will solve the problem.
As for smiling at us? Yes, it's fine and Yes I sometimes ask a question and the BACX/BA crew are always a delight. BUT - given the constraints of the galley/steps area AND the silly scaffolding, I think that this should be optional on the RJ/146 and other types with similar constrictions.
In particular - if they have only just done the first sector of the day, I'm sure that they would be better off turning the machine and 'relaxing' for a few minutes. Come to that, if I has just one last sector to do that day, I'm not sure that I would want to stand and smile at me.