Re: End/ Edit Item Feature
So the perks of registration primarily serve as a security measure for posting ads. It also pre-populates some fields if you are posting a new ad which saves them time. They can also login to your WordPress instance with limited access unless you password protect your /
wp-admin/ directory. For multiple ads they do need to pay for each post one at a time.
In the next release ClassiPress will be leveraging the user accounts so posters can view their old and current listings with options to edit, delete, and/or relist their ads. If users don't register, they won't be able to have access to these features thus making registration more important.
Hope that answers all your questions! I need to get to bed too.