I believe (could be wrong) that they just are against hosting NSFW communities on beehaw. You should still be able to view things from other instances if NSFW is enabled in your account settings.
I think so. I am not sure but I remember reading somewhere that beehaw blocked nsfw. There is a stickied SFW post on lemmyNSFW that is for linking NSFW communities to those who wouldn’t be able to see them.
I have an account on lemmy.world and can see more NSFW communities while browsing all communities. IDK if that's just a bi-product of them being more active or something beehaw does on their end and it just hasn't caught up with the influx yet, but either way it's fine with me. Beehaw ain't about porn, I'm perfectly fine having a separate account somewhere that is more about it.