1) There is no setting in the Vantage admin dashboard to rename the default "Business" text, so this would require customization of the default theme files on your part if you wanted to make the change. There is no encryption which would prevent you from making such modifications.
2) Events can be disabled from within the Vantage admin dashboard, and the actual "Add an Event" and "Add a Listing" buttons in the main page sidebar are optional widgets which you can configure without customization.
3) Yes, you would create a custom form if there are fields not on the default form that you wish to use. They can be linked to specific categories. Customers are redirected to PayPal to complete payment for their listing. This is at the end of the listing process. The default user on the Vantage demo site doesn't have any listings posted, but you can see their user dashboard
here, and when their are listings to edit, they appear in this dashboard with an indicator of whether or not the listing is live.
4) Technically yes you could as you could enable events and just not have the option available in the front end to create the events. Thanks.