1. They'd work best in a side view setup; for battle backgrounds I normally make them by making maps out of the tiles and usIng that as an image.
2. I imagined them as teenagers; you can use them however you want!
Ooh, that battleback sounds like a good idea. Incidentally tho I'm going front view so that all the characters can potentially be usable in combat, so I was initially thinking of the battlebacks in terms of like Earthbound or something. But yeah, some battlebacks made of key map locations sound like just the thing.