There is nothing specifically built into the theme which offers what you describe in terms of a link/offer appearing when someone claims a listing.. If you wanted to automate something like this it would involve customization on your part.
Listing owners do not have the ability to change a user rating or review. They can respond/comment on a rating though.
There is no feature related to the listing owner "harvesting" contacts/leads. There is a contact listing owner link in the listing only if the site visitor wishes to contact the business.
Google rich snippets is planned for a future release of the theme, however this is not currently available.
Listers can post links to their Facebook and Twitter profiles, but not specifically show the followers/likers information on the listing itself.
There is no message functionality built into the theme as you describe.
Yes, the Vantage theme includes a .csv import tool which will allow you to import bulk data. You can see this on the
Vantage admin demo.
If they add embedded YouTube code to the listing description, yes they can have a video window appear there.
No, there is no click to call feature at this time. Thanks.