pixelfed.org might be what you’re looking for.
I think it’s far down on their list of things to do unfortunately.
There’s also slide, but it’s very bare bones at the moment. Think you can only really log in and view posts and comments. A lot of copy over from the reddit app which hasn’t been updated yet.
Really should have read your edits before clicking those links.
Yesterday I saw a beehaw (I think) community thread which got locked by the beehaw mods but because it was federated ppl on other instances could still comment. I think !selfhosted would be still be up on your instance if lemmy.world went down.
It would be more hurtful to not use reddit at all. Lower user count will mean less advertisers willing to pay for their ads on reddit.
4 is a no brainer and 7 would be cool.