Thanks, Mr. Whelan:
DCC, digital command control, yes, I would want loco lights and passenger car interior lights to remain at constant brightness and two or more trains to be controlled independently on the same layout.
Yes, I fancy only DCC locomotives. I want realistic sounds as bell, whistle, horn, engine, airbrakes and so on. I want realistic sights as loco exhaust smoke. I want the vehicle lights to be operational even on static trucks and automobiles. I want a working travelling Santa sleigh with reindeer model on some kind on some kind of elevated track loop. I want sound recordings as "HO HO HO!, Merry Christmas!" and sleigh bells. I want the NOEAL sign on the mound to be illuminated and the model Christmas tree to be decorated with working lights and a star on top.
Many fantasy PHYSICAL model railroads can be drawn up in Trainz Surveyor. I'm sure some Trainz routes have even inspired some physical train layout designs.
The following video of my latest Trainz Christmas route is a virtual model of the PHYSICAL HO train set I envision. There is only one siding off the figure 8 main line with a bumper. Only one junction points. There is a couple of RR signals for effect. There are no complicated blocks at all. The passenger train would run a few laps, trade places with the freight train on the siding, vice-versa and the whole process would repeat itself over and over. Two trains trading places with one another would back into the siding from the mainline.