Available documentation for Vantage can be found
here, with information regarding the themes default functionality and links to the font and back end demo sites found on the
Vantage theme information page. There is no specific user manual outside of that as such, but as a customer, our support team can help clarify questions you may have about the theme in our forums.
In answer to your points:
1. If you choose not to moderate listings then yes essentially you can leave it to run without additional intervention as users can complete transactions and have listings posted without approval if you wish.
2. There are no default options or specific
marketplace plugins for the functionality you describe, so it would certainly require customization on your part. We don't offer these services, however we do have a c
ertified partners page where you can find developers for hire who are experienced at working with our themes if you are looking for someone to implement it.
3. Vantage has a built in .csv importing tool as shown on the
Vantage admin demo here. Thanks.