In the jive admin console > System > Management > System Properties i found the "jive.auth.disallowGuest = true" property. Changing that to false allows everyone to access /welcome, /people, /activity, etc. which i do not want BUT it does look like it adheres to the space permissions which if Everyone does not have access it does not allow it.
Is that the only way the Everyone space permission works or can i just make a single space public but keep the rest of the site secure?
Kerberos SSO may be an option if it is an internal community, so every user would log in automatically.
Use Permissions->Space Permissions page in Jive's Admin console (press "Edit Default Space Permissions"). This page also provides you with ability to change access rights to existing space.
I hope it helps you!