AA battery advice please?

I have the John Petrucci Majesty Monarchy 7, can anyone advice me on how long the Two AA batteries that go in the back of the guitar will last (see questions below).

Looking for this info please and is their a EB handbook for this MM 7 guitar that anybody might know about?

I do have the PDF (MAJESTY 7 CONTROL FUNCTION DIAGRAM 01-01-2016) and that helps but I was looking for more detail on the MM 7 please.

Looking to know:

#1: How long will the Two AA batteries last?
#2: Can rechargeable AA batteries be used?
#3: These Two AA batteries power the Mag Volume and Piezo correct and anything else?
#4: Any other Battery (or guitar maintenance advice or observations) that anyone can give?

Thank you everyone!

Byron Nemeth