At the top of your Dashboard you will be able to change your account to Test mode. Please note that Test mode only works with our basic implementation (payment screen), not with our advanced/API implementation. In Test mode you will be able to simulate successful payments, including payment notifications to your platform (IPN).
Yes, you can do this as long as the pages are on the same website. Due to compliance reasons, if you have multiple websites you will need a new Paygol account for each one.
Sure, just replace the image URL with your own.