Ok, I'm back, Big Al: First, thanks for reminding me about the Parts and Accessories portion of the e & e website. I had been there some weeks ago, but with all the different online resources, it's hard to keep track of where I saw what. I had not seen the Site Planning page, and that is pretty deep; a child adoption questionnaire, I imagine, is probably as detailed.
As far as RMH location, remember, my goal is first to warm soil that will sit above the bench and then to keep just the (by that time) greenhouse warm. The house is not a consideration. I do recognize that having the RMH on the west wall means it might be a good idea to insulate the wall and the floor, too. The other advantage I'm hoping to leverage is the window on the west wall, which I had hoped I could run the exhaust pipe out of. Going through the ceiling would be a real ordeal since the roof is flat and is covered with a rubberized leak-stopping material which I'd rather not disrupt if at all possible.
Your point about e & e "doing me right" is well taken. They seem like good people. When you say "I would make sure that they are aware that you are making a new inquiry and that there was confusion in the last round of e-mails", I kind've did that via multiple e-mails, calling twice and leaving messages for them to call me . . .
I don't know what else to do unless someone out there who has top secret contact with e & e can put in a good word for me. I think I'll stop typing for now. Thanks to all who care to be of assistance, you, especially, Big Al !