When I did my clean installation of XP Pro, I went into Windows Update see what it recommended, and there were about 60 of them! I didn't let it do the installations, though. I printed out the recommendations, studied it to see which ones I wanted, then went into MS Downloads and downloaded them manually. I saved the .exe files so that I wouldn't have to download them again when I needed them. This comes-in very handy when I install XP Pro in other computers.
As to whether or not you need the security patches, that's up to you. If you're on the internet, your computer is vulnerable. My suggestion is that you do what I did ... let Windows Update "look" at your machine and make it's recommendations, print it out, then go through the list one by one and determine whether you want them or not. Download the ones that you want manually, and save the .exe files, each one in it's own folder (so you can move them anywhere you want). That way you can save the .exe files, but also, once you have them all downloaded, you can install them one by one, and without being on the internet (installing with less stuff running).
When you have your print-out of the recommended updates in front of you, you should have a pretty good idea which ones you want, and which ones you don't. If you're not sure about some of them, all you have to do is post here and ask about them.
I hope this helps you.

Thanks, Son. Just what I wanted to hear. I like the idea of taking the .exe files and installing individually offline. Sounds like it would be much less disruptive.

Thanks again.