Using Discount Coupons in Appointment+

Hi

I have installed Appointment+ and MarketPress as I was advised I needed this to use discount coupons.

I use Discount Coupons for Marketing Campaigns and some clients get specific discount based on their corporate deals.

A few questions:
1. I cannot see anywhere the option of setting Coupons and Linking it to a Particular service in Appointment +
2. MarketPress has it's own PayPal payment gateway. I do not want to use this as I have already set up the payment via PayPal in Appointment+ (much simpler and fine for what we need).
3. My products are not physical as we provide training, so there is no shipment charges, returns procedures, etc. I just need to be able to issue Discount Coupons or Codes and nothing else from MarketPress.

Thanks for your help.