Could you provide some decent documentation/walkthrough on slimming down a
Debian based router/firewall concistent with your recomendations?
If you are really looking for an embedded firewall solution, I strongly
recommend that you do not go out and build your own.
I have worked with Coyote Linux before (http://www.coyotelinux.com/),
and found it ... irritating as all heck, but it was an embedded system.
I have also used a few others, most of which have died at some point in
the last decade or so.