Of course, nothing is infallible. Like you said viruses can disable it, but for that, they must enter your system before and if you have an antivirus and a good firewall that won't happen.
For the complex thing... you have a lot of friendly firewalls (like agnitum outpost for ex.) that have a database of lots of applications and it autoconfigures itself. Of course sometimes they are a pain in the ass like you say.
I have windows installed and without antivirus, firewall. etc. Instead of that, I have disabled all the useless and dangerous services but I look from time to time everywhere where the viruses normally act and I'm always alert and if I see a strange behavior in my system, I look for the cause.
A hardware firewall is very good but not if you fill it with holes (open ports for nwn, emule, bittorrent, etc etc.).
I agree with you in almost everything, I'm just being practical, it's just 2 different points of view xD
When I said that thing about dmz, I knew the risks but... what are the possibilities of being attacked by a hacker? we are talking about a private server of an old game not an official server of world of warcraft. I'm sure that he can sacrifice a little security
'>
This discussion can be endless
'>