1. Yes, everything in your itunes library will be saved as it currently stands.
2. You need to get some kind of external harddrive to move your songs over to a new computer. When you plug your ipod into a new computer, it states something like, "if it syncs to the new computer all songs will be lost"
I just got a new computer and I had to sync my iphone to it. It was the damndest because i-tunes grayed out the music on my iphone in i-tunes, i couldn't delete, add, etc.
finally i transferred all my songs over to the new computer and synced it. All is well now.
I hate itunes... its a bitch. Supposedly there is some kind of hack you can do in order for your ipod, iphone, etc to be synced to two computers.
hopefully I helped you out on your question.