Great feedback, everyone - lots to consider. In my case it would be yes to the covered tops due to humidity factors. My main concern was the vaulted ceiling coupled with the fact that the windows in this area are likely original/due for general replacement anyway. However, they are covered with plastic sheeting right now. Basically needed some seasoned opinions as to how viable of an idea this would be for longterm whole home heating use vs. individual fish room execution in wintry Michigan. I really did not see much information on this specific heating execution across the internet so thanks so much.
you are correct on sealing up bypasses in attic, wall tops, wire penetrations, anything that will let air into attic. If I only had a crawlspace, and the foundation was full of holes and what not, I would insulate the floor, problem with doing that is once floor is cold its cold. I would blow 16-20" cellulose into attic as that would give a really high R-value. It is possible to blow into existing walls as well, can pull clapboards off and go from outside or go from inside and mud and tape holes and paint. a word of caution on sealing holes in recessed lighting, they can heat up and burn out or catch fire, I used to insulate houses and can lights were always a pain.
Good to know on the recessed lighting. That is not something I would have considered.
