Blocking and defederation are not the same, just to note. If you block someone, I'm pretty sure they can still see your stuff. You just can't see them. Defederation would actually stop them from seeing your stuff.

You can't have an instance that runs on your personal set of preference unless you run your own. Somebody else went to the effort of buying a domain, hosting, handling moderation on their own time, and everything else that comes with running a fediverse instance, so if you sign up to that instance, you get to deal with their rules.

Even if you found an instance which suits your desires--which ultimately amounts to being essentially unmoderated, since you don't trust an admin to be in charge of moderation--you'd find it getting defederated by other instances because bad stuff happens in unmoderated spaces. What you're asking for, an instance which can access everything at all times, is fundamentally incompatible with the nature of the fediverse. I'm not being glib, but if that's what you're here for, you're in the wrong place.