Hi,
Sorry about the delay in responding, it's better to get in touch via our websites support forum - http://eventespresso.com/forum/event-espresso-public/
To answer your questions:
1) The premium version allows a variety of different gateways - http://eventespresso.com/features/payment-options/ (click the tabs for EE3 and EE4 at the bottom).
PayPal can also be used to accept credit cards, but this needs to be set in your PayPal account.
2) We don't have anything that integrates with online teleconferencing.
