In answer to your questions:
1. These are automatically sent once a listing has expired and the user is prompted to renew their listing.
2. There is no coupon functionality built into the theme, however if you wish to offer coupons to your listing customers you may like to look into the
AppThemes coupons plugin.
3. Yes, as you can see from the
Vantage demo site, there is a "contact listing owner" button on the listing page. Thanks.