You're right. I just looked and the CD-ROM is the SCSI device. How moronic.

Apple was a big believer in SCSI long ago, and I suppose they probably had a ton of SCSI CD-Rom drives still around. Who knows.

I was reading about the patching before loading OSX. What happens if I want to upgrade my CPU after OSX is installed?

That I'm not sure. I believe the patch is to get the installer to support the system, so if OS X is already up and running, it may not be needed at all.