My problems have been continuing with El Capitan.
Now it is iTunes that is really a mess. It is so slow, that it is barely functioning, with a beach ball lasting hours at times. My wife and I were trying to stream a movie from my computer to my Apple TV, and it froze up and stayed that way for hours. iTunes is just wrecked at this point.
I might have been able to fix Photos, so it goes to the correct Library. I had to use Fat Cat Software’s iPhoto Library Manager to do it though. When I opened iPhoto Library Manager 4, it showed 2 Libraries, and one was the one that Photos was trying to use, and it was an empty Library that I never created, and was showing up RED. So I deleted it, and iPhoto seems to go to the correct library now.
Still have been unable to get Messages to function at all, though I was able to make it go further by repairing permissions using Onyx, since that functionality has been removed from Disk Utility (as well as the ability to create Software RAIDs). And since it doesn’t even work for a brand new account, or after a re-install of el capitan I am kind of stumped.
My next step is to format another drive and install El Capitan on that and see if I can get Messages to work on that. I don’t really want to do that, but I can think of no other way to get Messages to work. My current system does go back quite a ways, so a clean install might be in order, though I don’t want to, as I have all the programs I want installed, but it looks like that may be my only recourse at this point.
Will keep updating to tell you how things are going.