Anyway, here's some of your Mac points addressed. All in my humble, of course.
- Safari and Mail are what you want to use; Firefox and Thunderbird have integration issues. Plus, they're slower. Plus, they look different.
- AV/Spyware software is irrelevant on a Mac. No, really; it is. You've been Windowsised!
- The base machine will run Tiger and Safari/Mail quite cheerfully
- You'll need a USB KVM, because the Mini has no PS/2 ports
- The Mini is appallingly cute. I have one[0], and it's just the cutest thing ever.
- Dunno about .mac; ask Rand or Todd.
- Office can be obtained for the Mac (and very nice it is too); the very casual Word user may find Pages to be more approachable, and it's Word-compatible for simple work. And it's cheaper. Remember that the Mini comes with AppleWorks 6, which is not unpleasant to use, and exports Word files.