For the first part I can't do this at the time, but I find that going back over my old photos a few months or even a year later I can easily delete the similar

For the first part I can't do this at the time, but I find that going back over my old photos a few months or even a year later I can easily delete the similar photos and find the most pleasing version. As for the second, I've become lazy - going to investigate syncthing.