Any chance on an updated re-release of the sets from the 80s/90s such as the John Bull, Prussian, Lafayette, or DeWitt Clinton? Maybe with DCC in a coach?
For under $300 so people actually want to buy it.

Cardboard and paint. If you want to go further, use plaster to make a little hill leading up to the crossing and paint that.

I finally glued the stiffening board to the underside of the foam and am currently waiting for it to dry.
I took a second look at the holes I made for the computer stand and remeasured their distance to the side. They are off-center by a few inches. I opened up my trackplan and moved some things around. I'm pretty happy with how it turned out. The only thing I needed to take out was the demolition house by model power.

Good to have an update, thank you.

First off, stop yelling. Turn Caps Lock off. Retype your prompt and you may get a response.

The Old-Timer 4-6-0 has been on your books for at least 2 years now. When is it coming out? Have you stopped planning and production? Are you in Beta testing yet? Do you need Beta testers? An update would be nice.

A weighted locomotive with a tender drive and DCC+speaker in a following carriage, or DCC+speaker in the loco and a weighted following carriage.
AT A REASONABLE PRICE.
Nobody is going to buy it for $400-500, and then you get to use the "well we did but nobody bought it" excuse to never do it again.

That is one gnarly truck, Shel!

Go to your local hobby store (Hobby Lobby will work) or big chain hardware store (Home Depot or Lowes) and get a set of small screwdrivers. I like the one from Hobby Lobby with interchangeable heads that all comes in a plastic case.

Those are just lessons I've learned the hard way from building yearly temporary layouts for myself and others in HO. Glad we could help you out.

You definitely want to use a latex caulk to set down the EZTrack and glue to set down regular track. Since EZTrack is by its nature easily removable and easily reuseable, you want to use an ashesive that is also easily removable. But most people who are using track without already-attached roadbed are trying to make a permanent railroad and have already made a few smaller layouts, so they would want an adhesive that is more permanent.

If it's plastic, a few passes from a small distance with a lighter should soften it enough to get it back in shape. But be careful! Too much heat and it will start to melt.

If it's metal, you'll just have to hit it with a jewelers hammer against a flat, solid surface.

Since you say it doesn't matter which car is last, I assume you've also tried them all backward and come into the same problem.

In real life, freight wheels and passenger wheels are usually different sizes, and when you scale it down, the difference is negligible IMO. But some manufacturers still make wheels in multiple sizes. You may have a mixed batch of wheels.

If your wheels are all out of gauge (too wide), they may pick the points on your turnouts, and the added weight of a car being pulled behind them might help keep the first two in line and bop the car back down onto the tracks. Since the last car has no extra pull on the coupler, there's no bop and off it goes. You might want to try putting a little extra weight over the last bogie truck and see if that's the problem, then choose a car and make that your designated last car. Or buy a matching Observation Car if available and weight the rear.

I would also check the rail connections really well. If the rail didn't seat into the connector right and is sitting on top of it, it will always pick up those passenger cars and cause trouble right before the special track.

The last thing you should check is your crossover, since most of your other cars don't have a problem.

On a small loop like this, should I put feeder wires on the tracks, or just solder the tracks together?

I believe there should be a parts diagram if you google image search for it, but I'm not quite certain.

Alright. So your worm gear is eating into your nylon gear. That's the clicking noise.
Something in there is slipping and making your motor spin faster than it needs to. Since it only happens in one direction (forward) I can assume that there is a little play in your rotor axle making it line up better in reverse. Lube the big nylon gear, and lube it very well with grease.