To be fair, people who buy know what they are getting themselves into. In other words, there's always an element of risk, and everyone can gauge that risk vs. potential reward and make a decision to go for it--or not. The entire Classifieds system is faith-based. Heatware helps somewhat, but it's not a guarantee. If someone wins an auction for a clack that's not yet in possession of the seller, it's up to them to negotiate delaying payment until the item arrives to the seller. This is relevant for people trading their spots for group buys, etc. It's something that should be agreed upon between the seller and the buyer.
But on that note, I do think it'd be helpful to add some formality to the Classifieds like Overclock.net has done recently, asking that sellers include recent photographs of their goods with a post-it or some note next to the item being sold, showing their user name and date. It's just a courtesy to buyers and a step to make the selling less compulsive and shady and more organized. Beyond that, this is not eBay, and still: caveat emptor. But both parties agree to those risks, so I don't see a need to reorganize the Classifieds too dramatically.
To appease some percent of the community and also to keep the Classifieds cleaner, we could institute a rule of no idle discussions in the Classifieds threads, including "GLWS"--only questions and answers pertaining to items sold. Posts like "Dude, I can't believe you're selling this already!" could be kept to PM's.
And finally, I think having the mods approve every single thread and modification to it is unrealistic, as you'd pretty much need a moderator or two constantly scanning the classifieds to make that happen.
P.S.: There's a "what is it worth?" or something like that thread. It could be used to estimate a price of an uncommon item, circumventing the need for an auction to do that.