Private notes are coming.
Patreon sort of thing:
Not exactly yet, though you can use... Creatsr? As a sort of patreon for plebs.
nostr:npub1m4ny6hjqzepn4rxknuq94c2gpqzr29ufkkw7ttcxyak7v43n6vvsajc2jl was talking about something like this yesterday.
Discussion
The thing I'm thinking of is private attributes, I think that would require more of a DID implementation