First, here's Norton's support page for Macintosh:
The question about running it off the CD or HD... the instructions for Norton install, as I recall, advise you to run Norton from the CD first to clean the system, and then install it onto the hard drive once we're sure there are no virii present.
NOTE that the virus definitions that Norton uses on the CD are already out of date. The first thing you should do upon installing Norton on your HD is to download the new virus definitions (via the Norton control panel), reboot, and then re-scan the entire system.
Second, a few general troubleshooting ideas:
1/ in pre-OS X systems (like OS 9), I find it helps to boost the memory allocated to the application that's acting up. Find the program icon (not the shortcut) and select "Get Info" from the file menu (or Command-I). Increase the "preferred" memory allocation. If you have lots of RAM (like more than 128 megs) try giving it another 10,000k.
2/ rebuild your desktop (reboot, and while the extensions are marching across the bottom of your screen, press and hold Command-Option until you get a message asking "Do you want to rebuild the desktop?" Say Yes.).
3/ zap your PRAM (reboot, press and hold Command-Option-P-R, wait for three chimes. yeah, kinda voodoo-ish). The Mac will continue booting up. You will find that some things need to be reset, like your General Controls panel, and a few other things.