Just one response about making track power wires to the tracks ...
The benefit of using Terminal Track sections is that the connection screws are visible and accessible for convenient circuit troubleshooting with voltmeter probes. Then it's easy to find a short or an unwanted voltage drop along the routes.
Hobbyists who prefer to hide track wiring for the sake of realism and avoid the "toy train" look, install power wires attached to track pins that can be hidden from view and dressed up underneath the platform. a very clean installation. But that method is more demanding to install.
I'm now 81, so "easy access" wins. Visitors to my L-shaped layout realize it's an ELECTRIC layout, so seeing wires at trackside attached to terminal track sections isn't an issue - for them or for me.
Carry on ...
Mike Mottler LCCA 12394