Your point about queries getting duplicates which crowd out some desired results is a good one. You could technically send one filter per pubkey with limit 1.

Lists should not have create/update like blog posts, they should instead have set/add/remove, which combines diffs and replaces in a conflict-free way.

From the perspective of event sourcing, projections should be a different layer from events. We have all this weird awkwardness because we have only one layer. I'm planning to work on some basic layer 2s via DVMs in the next month or so.