Jeff
I like your plan, provides for swithing and some continuos running, without a huge amount of space. Steam or diesel? I have just started in 2 rail scale, using a old Varney/GM B&O 4-6-0 as my loco roster, with some All Nation would boxcar kits. Gotta find a couple of Intermountain B&O hoppers. Going to handlay turnouts & track.
Enjoy, keep us updated
Mike P