While I acknowledge the technical merits of the application, I myself would never attempt this for the following reasons:
When I am not home, the "good" locomotives and Tangent freight cars are not on the layout because even though I can somewhat trust my own children, the neighbor kids come over and are way too touchy feely to the point of having previously damaged equipment that was on the layout. They will not listen even when told "no" by my sons.
So in practical terms, I learned the hard way never to leave anything of my motive power on the layout or within reach of someone less than about 6' tall. My son has his own engines and rolling stock that he can grab and use, even including a BLI 4-8-4.
If I'm not home, I would not want to operate my trains remotely--ever. Although my track work is very good, I'm just not leaving my good trains out. They are located on shelves above the layout, that only a tall person can reach.
This isn't about personal superiority or anything other than simply protecting or preserving the value of the handful of really good engines and cars that I am privileged to have.
John
I have not had any damage. There have been derailments and crashes but the stuff continues to run. I agree with your concerns and would not put anything really delicate or valuable on there. And if it became a problem I would run just one train and control the switch operation so it couldn't crash. Obviously nobody can touch it - they can just run it within the parameters you might set. It is good for showing off your trains if you wanted that.
BTW - I added a discussion board to the site if anybody is interested.
www.internetmodelrailroad.com