It seems that it is not possible to create a storefront without a door panel in the storefront element (at least in the US library for storefronts).
It also seems that it is not possible to create more than one storefront fixed panel to either side of a storefront door panel. I find that these limitations exceptional and makes the Storefront Library basically useless except in very limited applications.
Unless i am missing something right under my nose that allows creating more realistic storefront elements. i must be missing something.