Pretty straightforward.

The topic creators should be able to close their own threads. This could reduce the administrative overhead of threads that are "over" or that the original poster deigned over.

Just a thought.

Actually a pretty good idea, something rare in these forums

Possibly limit it to support and officially encourage it to show threads that have been answered at a glance.

But then, there's no real reason to limit it; it's not exactly abusable.

If we're talking about regional limitations, I would say it could be limited to anything that is question and answer oriented.

Support subforums for licensing, mod-making, etc would be the ideal place. But again, as Pauly said, no real reason to restrict.