For better or worse, I've declared the FWTK paper done. Barring small changes to correct errors, consider it in its final form.
For those new to the game, FWTK is the Firewall Toolkit, one of the first application proxies written 20 years ago. Amazingly, it's still usable. Combining it with other technologies (SOCKS, ipfw, iptables, Squid, other proxies/packet filters) allows you to build a workable firewall for just about any *nix flavor, including a Mac version.
If you care to read it, click on the Wiki link above and scroll down to the Security section. Let me know what you think?