By default, ClassiPress requires users to register before they can post ads, so yes once they have done so, they can manage their ads (edit/delete). There is a featured listing option which allows the ad to appear in the featured listings slider at the top of the homepage. If you set a payment option for it, this will publish automatically once the transaction has completed. Yes you can charge a mixture of free or paid listings, and determine whether ads are moderated before posting if they are free ads or incomplete transactions. There are single ad page and banner ad spaces, however you can purchase addons from the
AppThemes marketplace which can offer additional ad placement as well as other features so you may like to check those out. Thanks.