Placing Rail Served Industries On Layout Edge

[Gary S]

But still wondering about how I'd have to handle coupling/uncoupling cars.

If you left the wires on the kadee couplers, you could put an electromagnet at each of the places you would uncouple cars, and use those to couple/uncouple inside the building. Everywhere else, you could uncouple by hand. By having an e-magnet at each uncoupling location, you wouldn't have to do the moving back anf forth which is required for the delayed action uncoupling.