From what I can understand Laserfiche Discussions would take some tweaking to get it setup as a forum / comment / blog tool. Can this scenarios work?
Full user creates post/conversation, public guests can see the post (no login needed, like Web Link's auto login), and logged in retrieval users can comment on the post.
In other words, how can I get Laserfiche Discussions to operate like Laserfiche Answers with a public component.