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