I think Nostr clients should hide the key generation/management for a while and once the user is engaged, remind that they have to backup the keys, and explain how the keys work.. Don't overwhelm users with Nostr specific things.
Have some popular and some random relays. Everybody needs interaction in my opinion and without popular relays there is a risk of not being heard. Not being heard hits harder than centralization in my opinion.
Make it somewhat fun for the new user. "The algo" on the other networks is making the experience fun too, it is not just mind control! Help the user reach the best content on Nostr. This may be hard without LLMs but I guess DVMs are evolving.