Planning the 'mini' layout

I've been working on the plans for what I'm calling the mini-layout. This is because we'd still like to move in the relatively near future, hopefully with a room of an appropriate size for the layout I'd like to do.

One of the nice things about the mini-layout is that I have a lot of what I'll need to get it operational in short order.

Assumptions
Operations will be based on autumn 1951, second trick.

The maximum train length, based on the sixe of the layout and particularly staging will be about 20 forty-foot cars, plus locomotive and caboose. I might consider expanding this to about 25 cars or so, depending on how the plan comes out.

The Berlin line (and thus the Whiting Street yard) are offline.

All staging will be stacked in a single location allowing access from outside the scenicked portion of the layout. Thus staging will be hidden from the operators, but the design allows the person operating the staging to see the whole layout.

Operations
By focusing on a single trick, I can identify what I will need to roster in the short run. The trains that will run during a typical session are:
OA-4 May pick up and drop off.
446
HDX-5 Drops off and picks up, could return later in the trick.
131
AO-3 Drops off and picks up.
YN-3 Does not drop off or pick up.
157

Operators would be:
Staging
Local Switcher person/team
HDX-5 person/team
All other trains team

The person operating staging could conceivably run the through trains. The time between trains would be spent shuffling trains in staging.

RosterThe nice thing about this schedule is that I already have a good portion of the roster needed, for example:
(3) DERS-2b (RS-2) locomotives (I need 2)
(2) DERS-2c (RS-3) locomotives (I need 1)
(1) DERS-1b (RS-1) locomotive (I need 1)
(1) DER-1 (DL-109) locomotive
(1) DEY-3 (S-1) locomotive
(2) DER-2 (FA-1/B/A) locomotives (I need 2 FA-1s)

I will probably have the DERS-2b and DERS-2c by the end of the month. The DERS-1b is readily available. So the only challenge I have is finding more FA-1 locomotives.

I have all of the hacks already or on order. The only thing that will be difficult is the light weight passenger cars, simply because there is no model available. I'll need about 4 to start, but can substitute heavyweights in the meantime.

Construction
I'm still working out the details of the exact plan. Bill Schneider built his in sections on foam at his dining room table. I like that idea, not just because it makes construction easy, but a semi-modular approach means that I can move portions to the next layout. The only potential issue is the clearance needed when using 2" foam instead of plywood or OSB. Another factor is grades, but if I build the grades by simply tilting the foam, then the same base can be reworked for a level design in the future. The grades will probably be necessary for staging.

The final decision is whether or not I want to tackle a helix. My concept (particularly for staging) could be problematic due to the necessary location of the helix if I use one.