1. This is not currently a default feature of the theme, so it would require customization on your part if you were looking to allow this.
2. Vantage already has a review feature built into it, so the plugin isn't required for that theme specifically.
3. In Vantage, business listings are essentially services which can be rated, if you used products instead of listings then it would work in the same way.
4. Reviews are specific to listings as seen on the
Vantage demo site.
5. All information regarding the plugin is available on the
marketplace product page itself. Thanks.