Suzie

The track plan looks a lot more complicated than it is. There were basically two loops, a 'Union Pacific' and a 'Rio Grande' with two trains running on each loop. It certainly looked impressive and very busy.

You get four indications. Both lights on meaning the point is in a 'mid' position, and both lights off meaning there is no power to the track. This can be handy for quick fault finding.

The Hornby one should not need the link wire.

What is a 'pc' switch? The diagram is correct as long as you don't use a Peco passing contact switch - the wiring for a Peco switch is sightly different.

Quite big then.

How big is 37 000 square feet compared to other similar venues? At least it will have parking.

You can buy 'AC' LEDs which are ideal for this application since they don't require the protection diodes and therefore make wiring a bit simpler for the version 1 scenario:- Green AC LED https://www.rapidonline.com/truopto-osggd25111e-5mm-pure-green-ac-led-22-000mcd-15-56-2309 Red AC LED https://www.rapidonline.com/truopto-osrrj25111a-5mm-red-ac-led-5800mcd-15-56-2311 White AC LED https://www.rapidonline.com/truopto-oswwy25111e-5mm-white-ac-led-10000mcd-15-56-2314 Blue AC LED https://www.rapidonline.com/truopto-osbby25111e-5m

DCC stay-alives work best at low speed when the motor is drawing less average current. The Zimo one in particular is excellent when the train is almost stopped since it uses the stored energy to move the train along to the first bit of live track so as to keep everything powered up. While you might like to think of it as a flywheel it is a lot more capable than a simple flywheel, more like a flywheel with its own gearbox!

It would help really to decide to go for DCC or DC, it will save having to answer the same question twice! Your first diagram is how you would wire it for simple DCC with Insulfrog, for DC you just would not bother with the insulated joiners. If you were doing it properly for DCC with Insulfrog you would add a few more feeds to the dead sections and insulated joiners on the frogs as you have done in the third diagram which is correct for DCC with live frogs. Insulfrog is not like other varieties of dead frog as it needs to be treated the same as live frog when used with

The new 'Unifrog' points should address these issues.

PL15 will be fine.

Yes, it looks like the MX644 has not been produced, only the 21-pin MX644C/D variant. The version with wires is the MX645 based on the PluX 22-pin decoder.

I think that F1 on an American command station is likely to be the bell. F2 should be the horn.

You will have trouble with the ZTC because of the ZTC accessory numbering not matching the standard Expressnet numbering, but other than that it should work. It will not work with NCE. The routecontrol is best plugged in to a Lenz Expressnet panel or similar with a modular cable, and the expressnet panel can be wired to the ZTC.

1N400x diodes are 1A rating, but in a full bridge rectifier they are only in use half of the time so the bridge is 2A continuous rated when used on an AC transformer as in the H&M controllers and will handle a big surge for a short time without issue.