As far as I know Lemmy stores only text locally and images and such will be linked to the external instance. Text doesn’t use much disk space, so that shouldn’t be a big a problem. Sometimes when you browse Lemmy, you notice posts that have broken links to images. It’s because the other instance is down, but you can still see the text portion of the posts on your home instance.

There’s also pornlemmy.com. You don’t need to be logged in to view posts and there’s no anime/hentai or aigen stuff.

That list won’t show which instances have block the home instance. The blocked list lists only the instances the home instance has blocked, not the other way around.

It’s not a feature of Lemmy and, I guess, no-one has wanted to create it for their app. You should submit this idea to the Lemmy developers so it will eventually be a feature in every app.

Some communities have bots that copies posts from Reddit. Some do that so there would be more content in Lemmy. Those bots probably don’t break any rules set by the Admins of those instances.

Personally I don’t like that content is being copied without the permission of those who made the posts in Reddit. Also, in some cases it sort of defies the whole point of the community. For example, one of the Explain Like I’m Five communities has a bot like that. The bot includes a link to the original post. Why would anyone reply to the bot’s post, when you can just read the explanation from the original post? That doesn’t help make Lemmy more active place when a bot posts things and no human ever replies to them.

At the bottom of the page, it says something like “BE 0.17.4”. BE means BackEnd, in this case that would be Lemmy.

r/Blind mods created their own Lemmy instance at https://rblind.com/. They use some beta features and their own modifications to make it more accessible.