Yeah I can't say. Lemmynsfw didn't have a bot but you could have a bot that removes anything with that kind of flag until a human reviews it.

Regarding question one, lemmynsfw had at least one meme community.

2. I think most communities are run by only one mod.

If we all move to different instances though it's going to be hard for people to find their niches. We might need a porn community aggregator community.

Also lemmy.frozeninferno.xyz

I browsed a few sidebars and these instances didn't rule out NSFW: lemmy.org, lemmings.world, reddthat, lemmy.blahaj.zone, hilariouschaos, and of course Lemmy.world.

Ideally the priority would be one that doesn't require email verification.