I have to second John's comment about who the organizer is making a big difference. If John Craft is running it, I know what to expect and will sign up in a New York minute. For others I might have to ask around to get some feedback.
To answer question #5. "What is the one most imprortant improvement that could be made to most photo runs in your opinion?"
There really are two things. The first one is know your light angles and plan the location and time accordingly. I've been on trips that simply went from point A to point B to point c, stopping along the way without regard for the light. On a trip that pays attention to the light, you might go from point A to D, then back to C and back to B. Generally trips that try to cover long distances yield poorer runbys. Stuart Lovell used to say "minimum mileage, maximum photos." That's a good motto to follow.
The other is smoke. Learn how to make it and how to produce it at the right time and place. Some firemen take pride in running with a clean fire, and that's the correct way to fire, but photos need smoke to make the image come alive. That means a steady smoke trail at the photo line. Inexperienced firemen will bale in a pile of coal while waiting to start the runby. Then there is a huge cloud of smoke on starting which thins to a gray haze at the photo line! Not good.
The engineer should also make the runby at a steady speed. Opening the throttle just before the photo line to make the engine work harder and make for a more impressive runby simply makes it obvious on video that it's a staged runby, plus the smoke trail punches out and it's even obvious in the stills. Mike Manwiller is perhaps the best I've seen at this. He could run down a 1.5% grade, making the engine sound and the smoke look exactly the same as it did going up the same 1.5% grade.
Realize that different groups may have different expectations. Some people can't get enough of hearing the whistle blow. Others are driven nuts by constant blowing for non existant crossings. Find out what your customers want. Listen to your customer's comments from the last trip and practice to get better next time is the most important advice I can give.
Michael Allen