Two iCloud accounts syncing to 1 MacBook
My wife and I each have our own iCloud account. We periodically download (sync) our photos into Photos on the same MacBook Pro. This has worked great for us for a while. However, we would like to take advantage of iCloud, for backup purposes. Also, my wife frequently runs out of space taking pictures/videos of the kids. She would greatly benefit from the "optimize" setting.
My questions:
1. Can we continue to use our MacBook Pro as the "central hub" for all our pictures? Whether that is through connecting through a USB and syncing (like before), iCloud syncing, or otherwise.
2. If we go the iCloud route, what are the implications for our phones? Will we suddenly see hundreds of old pics show up on our phones?
3. Our goal is to have iCloud backups of all pics, to save space on our phones using the optimize feature, and to continue to have all photos from both accounts saved (in full resolution) on our MacBook Pro. Does this sound like a possibility?
Thank you!