I would prefer to lock any topic after a week of inactivity, and if there's someone who wants to post something serious (not just a oneliner spam), can click on a dedicated button, post a reply, but first the mods should review the post if the quality is OK to reopen the topic to include that post.
The former part is nice,but the latter,not so much. Mods don't have time to handle reports ,if it comes to a situation like this,things will slip out of hand,mods are assigned their jobs for moderating the boards and not for approving posts.
We can't expect the forum to be totally against spam,that would be impossible. If people are just spamming for bounties,things are already taken care of then: Merit. DT members(if spammers are caught cheating). And the Timelord2067 squad.
If people are spamming for some other reason,like getting paid for bumping ANN threads,spread fake reputation and all that crap,there is
patrol Loyce V to monitor that.