Will moving my photos to photostreams save my iCloud storage space? I've read here that photostreams do not 'eat up' the space however the post is quite old. If this is still correct, is the '1000 recent photos limit' applied per photostream or all photostreams?
According to the Apple Support Article My Photo Stream, "The photos you upload to My Photo Stream don't count against your iCloud storage."

The 1000 photos limit is applied towards the My Photo Stream album, which stores the most recent photos for 30 days.