I'm one of the members of David's A&O work crew.
As surmised the buildings were recycled from David's previous layout. For the open house David just set a few of the buildings on the layout to convey a sense of what the scenes might look like. The operating King Coal loader didn't fare well when it was in storage and will likely be rebuilt. The white foam core mockups in Mount Union are by fellow crew member Rick Bacon.
David's web site shows a lot of photos of his previous and much smaller layout. The most recent progress can be found in the A&O forums. This one is 2500 square feet and scenery has really just started. The entire basement including mechanicals, crew lounge, bathroom and work room is 3000 sf.
In the town of Linnwood (the dark rain room) that was actually day running, not night. During night ops the ambient light will be turned off, and the scene illuminated only by locomotive headlights, building and street lights. Road crews will need to carry a flashlight in their grips if they need to do any switching.
As for the lightning storm, there are 9 camera flash LEDs mounted behind the valence. Lightning is synchronized by an Arduino Pro Mini with an hour long MP3 loop. Between 1 and 9 of the LEDs fire depending on the strength of the thunder. For distant thunder the lighting strokes fire well before the sound.
The passenger cars are undecorated Atlas, which will be lettered for a private road instead of a Zephyr. The ABA F3s shown pulling that train are re-detailed P&D Hobby kits, not Atlas, which I weathered for freight service on the former layout. David did recently procure a pair of undec Atlas F3s for the train.
On David's previous O-scale layout we started to retrofit CTC after the mainline was complete. On this layout, we didn't make that mistake and built it in as the benchwork progressed. This has taken about 8 years, but CTC is fully operational except for one small CTC interlocking panel at a crossing. Some CMRI hardware resides under the layout. The CTC machine is custom hardware I built and is controlled by a $20 "Teeensy 3.1" processor board. All the programming is written in C++.
The track is all hand-laid, code 125 for mainlines and 100 for secondary. Switches are built in-place, including 3-ways, double slips, lap switches, and one with a moving frog. We anticipate about 18-20 operators at a time.
Many locomotives recycled from the old layout usedNCE 408 and old Soundtraxx DSX decoders. I'm gutting all of those in my engines and replacing them with Loksound V4 decoders and bass-heavy Tang Band speaker modules.
All the best.
Bob S