Quote: "something like customs or immigration rules" ???
Hè?!
What percentage of US based airlines is outside the US (= crossing borders) compared to Europe?
Why would the average US crew know anything about that?
More likely to be a European one who would know. But never mind that, most people would not ask the cabin crew anyway.
I am not to sure about the young/old comment unless you are ONLY talking about the cheap charters.
By the way, the food distribution was an example of input shown by the crew, not the quality of the food.