I have my eye on this exact set of problems and I think they are totally solvable.
Basic blocks are:
- private community-based relay (none of the naive users need to even think about or know about this)
- a simple Nostr client mobile native app that works just as a naive user would expect (think simple feed + group chat + DMs) and nothing more.
- the client would be configurable to only deal with a subset of relays at a time. A "context". So at first it would by default be set to the starting community relay. New users would only see that stuff and wouldn't have to know anything else exists
- IF (only IF!) they want to branch out from there, they could add other relays to a separate "context". So their default experience would still be their direct community, but they could flip into other, broader relay sets if they choose.
- no wallet, no zaps, no fancy NIPs. Installable from major app stores. Download it, enter your community's URL that your friend told you, and you're good. Hell, you could do all that with an in-person QR code.
And then naturally if they want to use other clients they can go wild into the wide world of Nostr as usual. But if not, they just think of this app as "their private community communication app" and they can stop there.