A good question.
A local answer.

Choose a performance if hearing or seeing a show in the venue is the main reason you are going. The programme, venue within the complex, seat view and running time matter more than the building's name alone.

Check the production page and box office directly for the single-show sales date; package and individual ticket releases can have different calendars. A package listing does not mean single seats are sold out.

A private transfer is useful when you value a confirmed pickup, need a child seat or have a group with a lot of luggage. Ask for the total price, waiting allowance, flight delay policy and exact meeting point before paying.

Allow daylight for the scenic detours and keep the final day's arrival flexible. The highway is efficient, while beach and lookout visits add time that map estimates do not show.

Compare the total room price and station access with a CBD alternative. For five days, the place you like returning to after dinner matters as much as the first morning's sightseeing convenience.

Tell the restaurant your curtain time when booking. A smaller pre-theatre menu may work better than a long tasting dinner, and you can plan drinks or dessert after the show.

Check which cruise terminal your sailing uses before booking a hotel or transfer. Circular Quay and White Bay create different luggage journeys, so a room that is convenient for sightseeing may not be the easiest embarkation base.

Look at the actual walking route to Darling Harbour, not just the distance shown on a booking map. With children, a short route without a difficult crossing can be worth more than a slightly cheaper room.

If the ferry does not fit your return time, compare a bus route in the Transport for NSW trip planner. Work out the whole journey from your accommodation, not just the leg to Watsons Bay.

Kirribilli gives you a north-shore residential base and a memorable approach to the harbour. Check the walk to the station or ferry from the exact property, because the area has hills and the last stretch can matter with luggage.

Choose a base where you can walk to useful transport and affordable food, then decide which one paid experience matters most. A public ferry ride and a free harbour walk can feel as memorable as a packaged tour when you give them enough time. In your daily budget, count airport…

I would split this into two half-days: the QVB, Pitt Street and the Strand for an easy central route, then Newtown or Paddington when you want smaller shops and a cafe stop. Markets run to different schedules and vendors change, so check the current operating day before…