Restart your computer. I've been through your situation.
Possibly but I think you can re-install it, right? That's what I would do.
Nope, the old macs use to have a disc, now they just have it preinstalled on new macs and no more discs.
Uninstall it go to app store reinstall it. It's not hard.
You won't, when you purchase a new Mac and sign into the app store, the iLife suite is placed into your purchased list.