Our site does not use Community Builder or Jomsocial so I understand that I would not be installing those modules. However the site does offer user account creation to produce registered Joomla user plus a separate subscriber list managed by AcyMailing (which doesn't require registration.)
So, how do I access the data collected by Payment Form - or do I rely strictly on the emails that it sends to me indicating that someone is registered? I assume event registrants do not need to be Joomla registrants, right?
In the back-end of Payment Form, there is a function called Payments Management . From there , you can manage (view, edit, delete) all the payment records .
So the answer to your question is you can access their data from back-end of your site .