Have an advanced mode of Big Picture Mode

I recently made myself a SteamBox using parts I had laying around my office. It works great and by replacing explorer starting up with Steam I save a lot of resources. But I find I still have to start explorer from time to time.
I'd much rather Big Picture Mode be expanced into a complete replacement for explorer with for example just a couple features I thought of, a basic file manager, and a wifi configuration tool.

Thoughts?

Have an advanced mode of Big Picture Mode