Regarding the passport and visa check, there are also large BA signs at both security points and by the passport and visa desks that indicate that you should have your passport and visa checked if you are on on of the required services with handbaggage only.

As for the announcements in the lounges, there were numerous complaints about these before and with the number of flights going from one terminal now, it would be almost non-stop announcements. Agreed that when the screens are working properly, it's an issue, but on a whole not having announcements means that the tannoy isn't constantly going off.