Looks like the post marking system is working, and I've marked several posts (in threads I started), as answered. I think the arrangement should work for most forums here, but more so where specific questions are asked (NORMA - Technical, for example). A forum like "Issues" may be better left to moderator/admin. My best advice is to monitor the feature, and check to see that it's being used as intended. Abuse of this feature is possible - but more likely where some status is given for providing "answers" as is done at ASP.net.
I suggest adding a section on marking posts to the Help page, at some point.
The feature should help in two ways:
As memebers and guests can see that an answer has been provided (or hasn't been, and they may have an answer).
If the feature is searchable, or is a filter option for viewing posts.
Hope it provides more benefits than headaches,