You're right, "borderless panels" is more accurate than "backgrounds" or "page backgrounds"; while I'd still like a term that indicates their relation to the other panels, "bottom-layered borderless panels" (or whatever) is probably too much of a mouthful.

WRT techniques, I think this is another reason why _Saiyuki_ was easier for me to start with than _Fruits Basket_, say--less techniques that immediately tried my "arrgh, need insulin" reaction, but enough differences from Western comics to perhaps be a gateway drug into more shoujo things later.