"Thing is, that does sound crazy to me. It sounds compulsive and anal retentive"
What a good AV and firewall whats wrong with that (something I would install on any system i worked on) maybe some of the other stuff is a little overboard but geez
"You know what I do? I install a modern operating system and pretty much leave it alone."
Yeap sorry don't consider this good enough you are just running on luck I have seen unpatched Win 98 and Win Xp systems with no firewall or AV that had been online not be infected with anything yet this was not the norm
"not engaging in high-risk behavior"
Your best bet along with at least a good AV software and a third party firewall or set up win 7 + firewall for outbound connections too.
Asynchronous inputs are at the root of our race problems. -- D. Winker and F. Prosser