thanks for the replies! I've just posted to the Interior Restoration, General forum, here
, since that seems like a good place to continue this conversation. (basically, my question is if it's possible to build a frame to suspend a cot over the dinette, or if that's completely unrealistic).
I've been eyeing those Command strips and glad to hear they will be good non-distructive ways to hang things. That's one area of modifications that will definitely have to happen! (I think we need a lot more hooks than the grandparents need!).