Regarding alcohol having to be served by a flight attendant:
I've seen several instances where people wanted to consume onboard something they'd bought. They mentioned this to the FA who simply said that they should give it to her to hold and she would serve it. I think this is due to a "not serving an intoxicated person" judgment thing, as opposed to a "bought outside the aircraft" thing. Having the FA serve it solves the problem. I recall reading here some time ago that this was allowed in premium cabins on AA, bit not Y.
Cheers.