Vaultwarden let’s you designate someone to take over your account if they request it and you don’t respond within a week

Not really. If that’s a hard requirement, check out what is supported by openwrt or freshtomato.

There was a similar question a few days ago with some points about wifi adapters vs access points brought up.

https://lemmy.dbzer0.com/post/36614200

You’d probably be a lot better off buying a decent access point (unifi, mikrotik, Aruba instanton).

Caddy with cloudflare support in a docker container.

Create your own emergency notification system!

Those never turn out well.

Running their own mastodon instance should be viable though.