If you're interested in getting WAY more detail on all of the aspects of that lawsuit, there was a truly amaazing and groundbreaking legal blog at the time called "Groklaw," run by a paralegal who was really great at breaking down every tiny move in the trial and contextualizing it to the larger battle. Was probably the start of my interest in following legal proceedings. She was so good at it that at one point SCO tried to depose her, believing that she was actually a front for IBM. The blog was sadly shut down in 2013 over privacy concerns, but it's still there, archived, although it probably isn't nearly as fun if you know the ending.
I forgot about this entirely. I remember it being a big fear, but I don't recall all the issues. I think there were even Distros that had versions accounting for what they didn't need from SCO.
No. It means that a case for the same incident cannot be filed again. When a case is dismissed without prejudice, it can be refiled if the plaintiff thinks they can make a better case at some future point.
https://en.wikipedia.org/wiki/SCO%E2%80%93Linux_disputes