I think I am one step closer to finding out whats going on.. I just have one question, but if needed, I included my phone number and availability in a PM.
I discovered the values which pp_confirm.php is trying to pull from WA_getSavedFormValue() are never set in the SESSION. The code WA_getSavedFormValue('CheckoutWizard_NewFromBlank_Default','SOME_FIELD') is referenced a bunch of times in the pp_confirm script. However, when I var_dump SESSION, I see blank entries for $_SESSION['CheckoutWizard_NewFromBlank_Default'] fields.
Where are these values set usually? I'm assuming WA_persistForm() is not being called to set the values being pulled in from WA_getSavedForm() on pp_confirm.
I also noticed a typo on my part in some custom bindings I added to allow for multiple shipping providers. However, upon fixing those errors and ensuring error reporting and display_errors were on, the pp_confirm script executes without throwing any errors, and redirects to the same success page referencing the non-existent Order Number 1.