Thanks for the reply. Your points are all valid and a focus in 3 and 4 solves the problem partially, but the downside is that people don't like spam so don't want small obscure relays so I don't think this will ever happen - people having 25 relays in their client.  But an even greater issue is that relay operators will come under pressure to censor from both  law enforcement and client users.  My fear is that Nostr ultimately has owners - client relay owners -who will always be held accountable either by govnts or by their customers.  The annonymity stops there and so then does censorship resistance. 

 Small relays don't need to accumulate spam.  I run a small chorus relay and only accept posts that tag me, and I moderate them for spam (which I haven't seen yet).

Nostr is no more or less censorable than the world-wide web.  Anybody can stand up a website.  Anybody can stand up a nostr relay.

If by "client relay owners" you are talking about clients that only talk to a relay managed by the client developer, then yes this is what many of us have been concerned about for a long time. Nostr doesn't require that model, and many of us have been pushing for a different model (the outbox model).