In public art galleries and the like you may see signs showing a camera with a bar through it - no mistake there. If in doubt just ask the attendants if it's OK. Private galleries probably don't allow it because of artist copyright.
Otherwise, apart from sensitivities towards taking photos of young children as in other countries, there's not anything I can think of.
Anyone in a public place can be photographed (not that they'll necessarily like it) but the definition of "public" doesn't automatically extend to the interior of commercial buildings or even shopping centres. In the latter case, security guards sometimes might question what you're doing but as they take no notice of teenagers waving their phone cameras around it's unlikely to be a problem unless you go out of your way to look conspicuous and an MP isn't conspicuous. Just play the tourist card if approached.
You should make the time to take a commuter ferry ride on the Harbour, say from Circular Quay across to Manly, walk over to the surf beach, and then ferry back again. They run every 30-40 minutes. Allow the best part of half a day. It's the harbour that really makes the city what it is and you'll get good views of both the famous bridge and the Opera House from the water. Both are close to Circular Quay. (It's not circular - more horseshoe shaped!) There are extensive Botanical Gardens to the East of the Quay and Opera House which provide nice views back to the city and over parts of the harbour.
I thought of another thing in Temora that might interest you - they have an excellent Rural Museum there which displays a lot of the early history of the area - old machinery abounds in sheds around the property as well as the usual domestic artifacts and records inside.
You probably know not to put ANY film in your checked in luggage but to carry it in your cabin baggage. That applies to both exposed and unexposed film. Your hand luggage will probably be X-rayed on arrival and certainly will be on departure at Sydney airport. The machines are claimed to be safe up to ISO 800 and I haven't had any problems with ISO 100/200/400 film. I used to be quite paranoid about it and demand hand inspection of my film after a bad experience at Heathrow years ago but it appears now to be unnecessary.
