This plugin is a gateway between your ZetaPrints portal and PayPal Pro. Use it to accept credit cards directly on your website.
The plugin does not store any details. It only passes the details between the user, PayPalPro and ZetaPrints. There is no data left about the transaction once the user leaves the payments page.
Credit card details are sent to PayPal Pro only.
It's not better. It is more flexible. PayPal may be a bit picky with some credit cards and decline transactions you would risk to accept yourself. In this case you'd better use this plugin and PayPal Pro.
Yes. Some interfaces are specific to ZetaPrints. You are welcome to modify the code and adapt it to your own system or shopping cart.
Contact firstname.lastname@example.org with your questions.