I did git ssb create ssb easy-ssb-pub then git push ssb master.

another idea for giving out invites in a more trust-friendly way could be to ask for an email address or other contact info before giving out the invite. maybe also ask questions like "how did you find this", "why do you want to join". then have it go into a queue to be manually approved. or just send it by email, thus confirming the address. then there is more of a connection with the new person

Agree. However, I'd do that for a v2.0. For now, I think it's more important to provide the quickest possible experience to join as a user.