Can I suggest a 3rd use case?
I have been pondering how to embed Discourse at the bottom of a blog or web page. As you know, standard Discourse cannot be embedded in an iFrame - apparently you resolved the cross-domain scripting concerns. The official technique to embed with Javascript requires navigating back to the Forum in order to add a comment, and though I understand why that is done I think a simpler solution would be nice.
So my question is - could you side by side design be the solution to the “embed Discourse” issue? I would suggest not having discussions on a paragraph level with the orange balloon (which would probably result in very few active discussions) but rather a plugin so a Discourse discussion is linked at the URL level with a web page. So a user would view a URL in his browser and a corresponding DIscourse discussion of that URL would appear. Presumably the admin could choose to restrict which URLs can be discussed a forum by either whitelist or blacklist or could allow discussion of any URL.
Thoughts?