The official name is the "System Notification Area".
Windows XP Pro is for business and home users. Windows XP home edition is for home users.
Yes, you can if you have a copy of the CD saved somewhere on your hard drive.
Yes. They use the same drivers, and virtually all software that runs on one will run on the other.
Nope, "sp2" means "service pack 2". Service packs fix bugs and (rarely) add features, but do not upgrade you to a different operating system.
Yes.