No problem, we're happy to answer any questions you may have :)
Currently Vantage is not a responsive theme, however we are aiming to have all of our themes responsive by the end of the year.
PayPal is the default payment gateway integrated into the Vantage theme, so is used for all price based listings. Outside of this, you can also purchase additional payment gateways from the
AppThemes marketplace if you wish.
You define the categories in Vantage yourself, therefore the type of listings can be for whatever you need them to be, so yes it would be a suitable theme for the project you describe. You can find some examples in the
AppThemes customer showcase for just some of the ways in which our customers are using the theme. Thanks.