[AberNStein]

thanks
re: the switcher and the projectors, we may well have to rent a video mixer. good point.
re: signal loss, my plan is to try it out and if necessary buy a couple signal boosters. i know for the projectors if the signal's not strong enough they won't display anything.
re:wax paper, i'm skeptical too, but it's not my job to make that happen. i just know right now they're looking at stuff that's cheaper than buying/renting a proper RP screen.
re:video black, I think we'll be ok; as far as I know, there aren't any blackouts called for, and the transitions will be videos.

thanks again