As a workaround, I could disable the Knowledgebase articles, comments, and News for the "Everyone" role. Then, allow "Registered Users with Verified E-mails" to access the Community and view Tickets. This would pretty much hide everything until the user has a verified e-mail address but still, the authorization process is a problem.
Is there an event action to place users into a specific role if their e-mail address has been verified and belongs to a specific domain(s)?
Is there an event action to send an e-mail once an e-mail address has been verified?