Alan,
Your logic makes perfect sense to me.

I like that idea a lot.
The only thing I would suggest is to prepare your PC-2100 for a significant towing condition. That is to do what we had done to improve the handling of our 2007 E350 PC-2350 motor home with tow vehicle. A travel trailer will play hard-ball with your PC's rear end and these upgrades will combat that very well.
These either replace existing components, or are added where there is none. A 2006 E350 chassis will not have any kind of rear stabilizer bar, nor a rear trac bar. The original Ford shocks, front stabilizer bar, and steering stabilizer are substandard for the extreme condition you are considering. The upgrades I state below will be real nice to have even when not towing, so it's a 2x benefit.
- heavy duty front and rear stabilizer bars (Roadmaster, Helwig or other equivalent)
- rear trac bar (Henderson or other equivalent)
- E350/E450 motor home specific shock absorbers (specifically Koni or Bilstein)
- heavy duty front steering stabilizer (Safe-T-Plus or other equivalent)
- realign your front wheels (often requiring offset bushings because the alignment can be so far out)
Given the heavy tongue weight of a travel trailer, you might also consider rear air bags, though I have no first-hand experience with them on a PC.