I decided to wait a few days before going to Beta 2, to see if anything bizarre erupted. When there were no great alarms, I downloaded Beta 2. I read the warning not to interfer when it took a long time to import the library from Beta 1, but after an hour, thought, "This is ridiculous." Went to the Adobe site, and found out that it's some sort of bug that seems to mostly affect IMacs. I forced-quit Lightroom, as suggested, then restarted, and everything was fine -- the library had been imported.
But now I had two libraries, one in my default drive in the Applications folder, and one in an external drive, where I'd decided to keep Lightroom. The external was Beta 1. I dragged that to the trash, and copied the new Beta 2 to the external drive.
So here's the question: I now have two Beta 2 libraries. If I just leave it like that, considering the one on my default drive to be a back-up, and working only out of my external drive, will I run into problems? Like in, conflicts? Since my Photoshop is on my default drive, in going back and forth to Lightroom, will it look first to the default drive Lightroom, or will it automatically save it back to the drive that the file originally came from? Any other likely problems?