From my experience, the buttons on scanners never seem to work right (even on PCs). I would suggest opening the program you want to scan from, and using the scanning features that way.
I have never used Eudora in the past, so I can't help you there. Have you tried Mail.app? It works wonderfully for me.
What game is that? Almost all games nowadays need to have the CD in the drive for copy protection.
The setting you need to check for the Date in the menubar clock is located at SystemPreferences ->Date & Time - >Menu Bar Clock tab ->Show Day of the Week.
I hope this helps a little.