You can see an example of Classifieds integrated with vB3 at http://www.photopostdev.com
Ads are only moderated if you want them to be; you can disable moderation of ads by usergroup. Is there a way to locate all of the ads that a specific member has posted and edit/suspend/delete their posts?
Are you asking if you can delete all ads by a user? The answer is YES, when viewing their profile (PhotoPost Classifeds profile, that is), there is a DELETE ALL ADS option that will remove all ads placed by that user.