Is it possible (and if so, how) to configure WordPress blog to support these feature for user comments? I want to use built-in comments, not 3rd party services like Disqus. If something cannot be achieved by configuring WordPress itself please suggest plugins that can achieve the following:
- Every user that would like to leave a comment must be authenticated
- Supported authentication methods must be Google, Twitter and Facebook auth, no other (e.g., it must be impossible to log in using generic OpenID provider etc.)
- If a visitor provides an email address, they can check a checkbox to be notified of new comments
- Comments should be flat (not visually nested) but should allow references to other comments.
- If there are too many comments, they should be loaded dynamically as user scrolls down (i.e., similarly how Twitter or Facebook work).
Can this be achieved using WordPress built-in comments plus some plugins?