Marking the potential run-by sites is certainly possible, although labor intensive. My experience with the D&S-run trips has been that the numbers of run-by sites have been really limited (typically 6 or fewer), when compared to a typical charter operated by one of the 3rd parties (Friends, HTP, Lerro, Franz, Hansen, etc.) Another problem with this is that on the C&TS, most charter operators have a pretty large list of potential run-by sites, and PIC (Person-In-Charge) operates a bit like a football coach on game day. They have a game plan for the sites they'd like to hit, but as the day goes on, they continuously consult with the Conductor and the plan gets modified.....sometimes considerably......based on schedule glitches, weather, WATER, meets and a multitude of other considerations. For a C&TS Charter, I think the idea of marking would be considerably more difficult than on the D&S.
The D&S trips are also different from a typical 3rd party charter with regard to the number of people. On the D&S trips, 75-100 is common. On 3rd party trips, 30-60 is the usual range, with 30-45 being the most common. The smaller group has the advantage of being able to stop at tighter locations, and to allow a little more flexibility with respect to photo lines. Obviously, the smaller group also has higher ticket prices, but that tends attract mainly folks who are very familiar with procedures.....meaning they don't wear red and stand right next to the locomotive.
On most 3rd party trips, there is an established photo line....sometimes more than one. You can shoot from someplace other than the photo line, but you cannot foul the photo line shot. It works pretty well most of the time.
With regard to folks getting along, I would say that they do 95% of the time. Occasionally, there are folks who take things (and perhaps themselves) way too seriously, and there have been a few interesting "discussions." These outliers seem to be spring-loaded to yell at the first person to walk into the field of fire, even if the person is just doing some weeding, 5 minutes before the train comes. There are those folks. Most however, are more easy-going and are there to have fun. The various Charter Operators have slightly different styles, but most of them are pretty good politicians and are pretty good at settling personal disputes. The key thing is that someone does have to be in charge and be the final authority as to what happens and they cannot be afraid to make a potentially unpopular decision.
/Kevin Madore