This question has been partially answered here: the apple id you entered couldn't be found or your password was incorrect
My application has been approved (along with the in-app Product) and is "Pending Developer Release" (I configured 'Version Release' to 'Manually release this version' so that I can test the auto-renew subscription model with a real itunes account).
Can I test in-app purchases with a production iTunes account with an application in the release state of "Pending Developer Release".
Nope. :)
Best you can do is use a TestFlight build but that still validates against sandbox only.