Hi,
So after about 4 days and several Plesk support staff later we've got to the correct answers to the following questions about integrating Amazon Route53 with Plesk. (ras_koomohost you were correct). We're using Plesk 12.
########## FROM PLESK SUPPORT, Parallels #1930590 ############...
Info removed here as incorrect info given from Plesk support.
Please see below Q&A which I have been told it is definitely correct (got ticket escalated in Plesk support).