Well, to answer the question on UM policy of Amtrak, is that UMs under the age of 11 are allowed to ride in daylight hours ONLY and with the proper paperwork between staffed stations ONLY. Does this happen all the time, NO. A lot parents just find it convienient to drop them off at the station with a ticket to send them off to the other parents. I found, one time, a kid who couldn't've been more 11 or 12 riding by himself. He said his brother, who I saw right before they got off the train and was about 19 or older, was sitting at the other end of the train had his ticket.
I wasn't happy but I sent him to get the ticket from the brother and kept my eye on him the rest of the trip.
There have been times when accompanied minors have caused problems on night trains. Kids these days need more control and disicipline. I don't agree with dumping a child off on a train or a plane. I think the child SHOULD be accompanied and not babysat by flight crews or train crews. Too many things can go wrong to both the child and a possible innocent by stander.