Once in a lifetime trip - make sense?

Hi everyone I am planning to come to Australia (as a Brit) at the end of Jan/early Feb for 2-3 weeks. Can you please let me know if you think this is a good itinerary or if you would make any changes?

Fly to SYDNEY - 5-6 days Opera house Bondi beach Brunches and restaurants Exploring - open to suggestions?

Go to Airlie Beach or Hamilton Island 2-3 days White haven beach Any other recommendations?

Fly? To Brisbane for 1-2 days (so that I can get the next flight) visit Byron on a day trip

Fly to Perth - 5 days Any tips or advice?

End trip