No one has yet chimed in on #17612 (re iTunes transfer and Mail & News-groups). Do I take it that neither item is possible?
Your iTunes file structure differs from mine, i.e.
"In my OS 9 folder I've got 2 folders - one called iTunes Music and one called iTunes Music Library," whereas I've got an iTunes Music folder and an iTunes Music Library.xml file, so I can't help you as respects your question.
On the other hand, though, you can simply launch iTunes on your new iMac, hit command-O (Add to Library), direct the dialog box to the appropriate folder on your (FireWire cabled) old iMac, and let iTunes do the rest. (This may not be the fastest import method, so it may pay you to wait for further input.)
Sorry, but your Mail & News Groups question is beyond me.