Clair, those are very pretty setups you’re doing! Great Public relations effort on your part, good for you!
I, too, set up displays in public. I’m afraid I’m not very good at watching trains go 'round, so my displays are a little different. They are layouts that kids can run themselves on tables provided at local train shows.
An Inglenook Switching puzzle for the older kids, & beside it for the younger set, a twisted and deformed continuous loop with an alternate route and a couple of trailing point spurs. During the setup I concoct a tunnel from my packing boxes, a blanket and a spare tunnel portal, and add some buildings and trees. Simple, not nearly as pretty as yours, but always a big winner at the shows!
The train on the continuous loop is made up of gondolas only, so the kids can give toy animals and other figures a ride.
As these are indoors where rusting is not a problem, I use Bachmann tinplate track, an enormous help, because it is very lightweight for carrying. However any helpers will need practice as the joiners can be tricky to assemble correctly.
Part of the solution is that I store the track in bundles of tracks ‘pre assembled’ into 4’ lengths and quarter circles. Very convenient. When I need fewer than three curves I can break down one of my quarter circles. I also cobbled together a couple of permanent power connector tracks, basically a slip of phosphor bronze pinched under each rail and a terminal screw thru it and the tie, held by a nut underneath. When I pack up I just wind the wires around the track. Usually wiring it all up is pretty quick and easy.
I really like the little B’mann hand-held throttles - cheap and plentiful - I have cabled up mine to be a little more rugged than they come from stock.
For the Inglenook, which is also Bachmann Tinplate track, but pretty well all long straights, again I bundle this in 4’ lengths. (4’ fits in my car.)
The two elements of my display are packed away individually. The Inglenook requires 8 different freightcars and a pack of matching cards, all of which I pack into a large carton or two.
Like you, I take a couple of spare power supplies along, and spare locos too. I have a couple of volunteers who come along and guide the kids for me, as both displays are too much for one person when little kids are at the controls, and usually the parents want to ask me questions, so usually I’m kept pretty well occupied by the grownups.
I get a little damage each time, nothing that isn’t easily fixed, and I sort of expect it and I don’t mind - a loco bell went missing last time, for example, and I won’t bother replacing it. I use stripped-down equipment, not fine models for this.
I like to give youngsters the experience of actually playing with these fabulous toys!
I was immediately taken by the overall attractiveness of your displays! Good luck with all your efforts! 
