You’re correct, the latest 5 links are not a huge deal, since there are only 5 of them. It just dilutes the search experience, and from what I can tell, makes it more difficult for the search engines to figure out what the thread is about. (The latest 5 posts do link to threads, and not just the posts)
For example, I have some Geico-related complaint threads (see complain about Geico insurance), where Google can’t figure out that this is an insurance-related page. Google keeps serving ads for the Chrysler 300C! Can’t figure out why, except for the latest 5 link. I’m thinking about shutting it off until I can find a fix, just to eliminate it as a source of the problem.
I posted this question on the TSMF site, and rec’d an email from a guy saying he had a fix for it. If I receive it and it works, I will post it back here and let you know.