Another comment about the camera issue - how often do you see people taking photos with the flash when it's not needed? Enough people don't know how to disable the flash on their cameras, to the extent where I'm OK with not allowing them to be used on a plane. The high-tension discharge that makes the flash can affect other electrical items (try talking on your normal landline and trigger a flashgun).
Admittedly, life would be easier if all carriers and all cabin crew had the same set of rules - they could be published, handed out by travel agents, and eventually the pax would learn . . .