Managing iCloud+ and Photos on iPhone and iMac

There's a lot here! I would use the iMac as the "Boss" of the system. And I would have at least one external hard drive connected to it with a Time Machine (or other) backup. You may need a second external hard drive, depending on the amount of free space you have on the iMac's drive. The iMac is the one place where you can add storage as you need it. You need to keep at least 10% of the iMac's internal drive free-- more is better.

How much free space do you have, now?

One reason to use the iMac as the main storage is that you can have more than one Library on a Mac. This means that you can keep all the pouting pictures, and others that may be good but not so shareable, in a separate Library. And you can keep the best of the older pictures, as well as the most recent ones, in a Library that you share with your phones and iPads through iCloud. Of the several Libraries that I have, my "Favorites" Library is the only one connected to iCloud.

On your iMac, do you use "Optimize Storage" turned on? If you don't, then you're good. If you are using "Optimize," then your iMac doesn't have all the original pictures, and so that needs to be fixed. We'd need to discuss that.

Since you've been moving pictures around with cables, you'll need to make sure that you have all the pictures in Photos on your iMac. With both cabled pictures and iCloud pictures floating around on different devices, some may get lost. You need to get them all in one place-- on the iMac.

We can do details as needed. What do you think? Was this too much?

What I did was duplicate the Library I had, and then I started deleting.

The favorites must be designated as the "System Library" in Photos' Settings>General. Only the System Library can be connected to iCloud (in Settings>iCloud.)

"Use as System Photo Library" is grayed out here, because it already is.

It doesn't work to change which Library is connected to iCloud. If you decide to switch from Favorites and connect the Pouting Library to iCloud, then Photos would suddenly see new pictures and upload those to iCloud, adding them to what was already there. So you'd get all the pictures again, and they'd be copied to all the other devices.

So I'm guessing you might have a Hubbies Library with his pictures, a Pouting Library with your pictures, and a Favorites Library with the best of both worlds and with all new pictures that either of you take. So all new pictures automatically get shared with the iMac and with everyone. Periodically you'd copy the appropriate new pictures to the proper unconnected Libraries, and leave the best on Favorites.

Most of us who do this (maybe everybody who's doing this) use the trusted 3rd party app PowerPhotos ($30) to copy pictures around Libraries. It's makes things way easier, and it does lots of other useful things, too. For instance, Photos on its own won't copy albums between Libraries, but PowerPhotos keeps the album and folder structure. I keep PowerPhotos open on my Mac pretty much all the time.

I have a Nikon Library for pictures I take with that camera. I take a lot of bad ones, so I curate them in the Nikon Library, choosing my favorites, editing, commenting, and rating them. Then I copy the best ones to Favorites. I also copy the iPhone and iPad pictures and screenshots from Favorites to an iPictures Library, and I erase all the stupid ones from Favorites. I also have Libraries for Old Family Pictures that I've scanned.

Anyway, that's what I do…