I'm in the process of finalizing my pro-sites installation and have decided to add STRIPE payments in addition to PayPal before I go live.
When I went into the settings to enable it for testing, it seemed odd that there was no place for credentials, but I didn't think anything of it, figuring perhaps it needed to be enabled first. WHen I enabled the gateway and clicked SAVE CHANGES, all my settings for all the payment gateways were nuked (Fortunately, I only had sandbox credentials for PAYPAL as well as some temporary text in the manual-payments gateway).
At the very least this is unexpected behavior. I'll dig and see if I can figure out what it is, but if it's a known issue let me know.