i may be wrong but i think alot of you stuff like themes and what not can either be found in /usr(/local)/share/fluxbox or ~/.fluxbox. as for the background i never managed to get any of the documented ways of getting a background set so i edited my favorite them and used:
Esetroot -s /path/to/image
in place of the theme RootCommand:
and i used Esetroot because bsetroot never works for me.