Hi Bill, welcome to cruise-chat. To be safe, I wouldn't book any flight before noon. You never how long it will take for debarkation to complete. The cruise line will work with you to get you off as quickly as possible, but you have to work with government agencies which have their own time schedules. Best wishes and have a wonderful cruise!
Hello bill the traveler, and welcome from me also;
you don't mention what time you arrive in Papeete, but assuming it's the usual early a.m. arrival (around 7:00) I would say there is zero chance of making a 8:30 flight.
Penny is right: don't book anything before noon to be safe.
Have a great cruise. I'm dying to try one of the smaller Princess ships.