1. Sensible photo organization.
It is an endless topic of discussion. I use iPhoto synced to iCloud for my iPhone shots, SmugMug galleries for sharing iPhone and camera shots with my friends and family. Finally there are Lightroom Catalogs for Archiving and Editing. Keeping all three systems in some organized form is a major challenge.
2. iPhoto issues.
Turns out that old iPhoto catalogs (6 years old ) are incompatible with new iPhoto. So I have to manually extract the photos from the catalog package and reimport into the newest version of iPhoto. That is a major pain and I've been procrastinating to do for at least a year.
There are also plenty of compatibility issues between versions of iPhoto. I get that new software brings new functionality, but my iCloud is synced between 3 different Macs: MacBook, Mac Pro and iMac. All three have different versions of iPhoto, and I often can't edit some photos on one machine, but can on the other. It drives me crazy to have to switch between computers just so I can edit an iPhone shot because it is in the new HEIC format.