How about get a new gmail address, change your account to that, use the craigslist style hidden email response for your ads, and then wait 3 or 4 days after posting ads before contacting the interested parties? Odds are good when you finally do respond with "Sure you can come look at it, my name is Jim, I'm at 555-5555, 123 Fourfive St." your post will be flagged soon, but at least in the interim this will allow you to sell some of your stuff.
And beyond that, if this guy has tried to incite people to rob you, that is clearly a threat, and your police are being very negligent about not pursuing this. Possibly they are daunted by the technology aspect of it, so if you have any of the legwork done (That they can verify) present that as well, or do some legwork, or do a honeypot type trap or something. If he actually calls numbers to determine if the ad is being sold by you, then that's probably a good way to identify him right there unless he's using a prepaid cell phone.