Hi Brett, in answer to your questions:
1. PayPal, which is the default payment gateway built into the theme, does not support ZAR, however there are other
payment gateway plugins available in the AppThemes marketplace which do support your currency and can be used with Vantage.
2. No, there is currently no option from within the Vantage admin dashboard which would disable this functionality. It would currently require customization of the default theme on your part if you were looking to remove it.
3. Changing the theme to custom color scheme would require some knowledge of css. You can find some more information about general theme restyling
here. Thanks.