Backing Up Programs For Leopard

I just purchased an external hard drive last night and after making a bootable clone to my hard drive through CCC, I am wondering if there are more things I have to do for two certain programs, as I plan to install Leopard as an Erase And Install.

1. iTunes - Since I made the bootable clone, do I really have to do anything else here? Once I install Leopard, would I just merely copy the music in the iTunes Library folder on the external HD into the iTunes Library on Leopard? Also, do I have to deauthorize my iTunes account before installing Leopard?

2. Firefox - I use Firefox and one of the things that I use extensively is AdBlock. Over the last several months, I have been able to block out several ads. If I upgrade to Leopard, will I lose all that information and have to start all over again or is there a way to preserve those settings within Firefox after the installation

Any help is greatly appreciated. Thanks!

 

Thanks, Eldorian. So, do I have to worry about deauthorizing my account on iTunes? And since the Firefox add-ons are in ~/Library, should my settings and sites that I've blocked also be preserved on there, as well? Thanks again!