Kevin, your story about people in the charter reminds me of the first charter the Friends ran in 2005 for a long time because of lack of serviceable locomotives. We stopped just past Lobato and they asked everyone to go to the West side of the tracks for a run-by, yet there were about 6 or so knuckleheads who went on the East side of the tracks and got into everyone's photos and videos. They then had everyone cross over to the East side of track for another run-by, and guess where the same six went?
Letting everyone in the charter know before, and reviewed again at the beginning of the event what the rules are and who is in charge will go a long way to assure harmony on the charter, and that way everyone should have a good experience.