- To encourage engagement at the initial stage, we have an auth wall for content inside the community, but community owners can change that when they create and choose their domain.

- You can create a community and explicitly mention whether you want your community to be listed and available for search in the community marketplace. The community owner has that option.

- Yes, logins are the same for all communities (like Reddit), currently there is no option to have a different secret for each community. But that sounds like a nice feature to have a separate identity for each community, hmmmm, I will add it in my bucket list and will think about it more.