Well, how can I get a feed that I myself curate? If this isn't possible, I don't see this thing taking off.
goat
If I make an account on some random instance that has nothing filtered, will I still be able to interact with these communities?
I'm sure it's possible, maybe ask on support?
Simply block it.
There is!
Click Communities, and from there you can sort Local (Communities that originate from your instance, for you it's lemmy.world!), or All, which includes most communities every public instance (like how I'm commenting to you from beehaw.org!)
From there, simply subscribe to what communities you like, even if they come from a different instance.
Abnormal behaviour. Putting things where they don't belong. Poor memory
I predict Reddit backing out, lowering the API price to something realistic, and then everyone forgets what happened, like every other time something like this has happened.
Is there no instance out there that has full freedom so I can put whatever I want in my feed?