Here's a random thought... How about posting in the FS forums only be open to High Rollers. If it was based on post count, you'd end up with more inane posts. But if it was invitation only, then we wouldn't have people with no track record here posting FS/WTB threads. Newcomers could still PM people regarding items FS or in repsonse to WTB threads, but they would have to contribute before being able to peddle their wares.
Just a thought...
:shrug:
If any of the mods think this idea will open a can of worms, then feel free to edit or delete this post.