Metropolitan, you provide a considerable amount of informative discussion and have some detailed posts that many read with varying perspectives. The word "restricted" though, may be what's discomforting. However, one could run a voluntary thread, such as ACC FANS ONLY post. That still would not prevent others from injecting comments, but may attract those that favor it.
To do a restricted system, registered posters would have to enter prior profiles for marking/labeling, and guests would be even more confined. Also, people registering could provide alternative information contrary to particular fan purposes. It is the Internet as well, so controlling such would be quite limited. Also, qualifying speech would be an issue as well as narrowing the diversity of perspectives.
However, again, to offer certain threads as fan-oriented, may have some merit. In short, SportsKC conveyed a "no" as to the general question, and personally, I concur. Thanks for the question.