@SNAK3ATER Per the Steam banner scraping, we're using the official steam banners right now, downloaded from http://cdn.akamai.steamstatic.com, which I think is official. We can certainly add more in the future if there's a good site with an API that allows for searching. Currently Steam banners are only downloaded for Steam games, of course.
We already have a sophisticated image type fallback strategy that works via the Image Priorities settings in the LaunchBox options. It looks like the main issue though is that there are no image priorities settings for Steam banners or banners. You could certainly hijack one of the existing categories though to customize it however you like, and then use that in the theme, though it would probably be better for me to add options for Banner Priorities.
Makes sense about the game options view.