under your user -> settings -> blocks tab, you can block specific communities. And there's an NSFW block there or under the settings tab if you want.

Filter out: beans

So you're talking about a sort of negative subscription. THat is ... "All" but not (a, b, c, ...).

Nope.

You may want to post this idea in !lemmywishlist@lemmy.ml.

Generally though this issue has come up before and is on the roadmap in same way at least in the form of "multi-communities". But your specific request here is different enough that it might be worth bringing up. I'm not sure it'd be a high priority though.

https://github.com/LemmyNet/lemmy/issues/818

You can certainly block communities in Lemmy – I've done that plenty of times. However, I don't think wefwef supports that yet, as I've looked all over and haven't found it.

EDIT: I need to amend this and clarify that it's Connect for Lemmy that's been allowing me to block communities, instances, and users. I hope all apps included this feature.