Tour trains North of Healdsburg? Been there and done that, over a decade ago with the Redwood Explorer!. Angelo (of recent book fame) and Carl tried hard with this and having worked it a couple of times, I thought it was well received by those on board. It was a bit too long of a ride though for some and a lot of passengers were sleeping on the way home.
Unless there is a real need, C/dale or Ukiah would be preferable ridewise and a more realistic timetable. This won't help the Skunk; timing wouldn't allow a daytrip connection meaning an overnighter in Willits. Also its going to be difficult to see Healdsburg as a base of operation even with the turntable, which surely can't be of much good now. Railroad land is prime building space nowadays and the town is more interested in gentle tourists as opposed to a trainload, a couple of time a day.
But the problems are well known, tunnels, floods, land slips even earthquakes, not forgetting the ubiquitous NIMBYs; enough to put any potential operation off!