edit this code:
$RecipArray[$CurIndex ][] = "".(WA_getSavedFormValue('[FORMREF]','First_Name')) ." ".(WA_getSavedFormValue('[FORMREF]','Last_Name')) ."|WA|".(WA_getSavedFormValue('[FORMREF]','Email_Address')) ."";
to:
$RecipArray[$CurIndex ][] = "".(WA_getSavedFormValue('CheckoutWizard_NewFromBlank_Default','First_Name')) ." ".(WA_getSavedFormValue('CheckoutWizard_NewFromBlank_Default','Last_Name')) ."|WA|".(WA_getSavedFormValue('CheckoutWizard_NewFromBlank_Default','Email_Address')) ."";
for the ajax issue, I'll need to troubleshoot directly, see the private message section.
NOTE: Please don't paste the page code into your message, attaching the php file is much better.