Whether you get exemptions or not depends how picky the CAA are being. The requirement for exemption of approved training for the theory exams depends on the applicant actually holding a current and valid ATPL. If you actually held a CASA ATPL they might let you take that ATPL skills test at an EASA ATO on the A320, revalidating the rating at the same time. For a CPL holder even with your hours.....more tricky.