For anyone seeking an answer to the landing/parking charges question, I managed to get in touch with Canberra Airport via phone today.
The landing fee is included in the parking fee. The parking fee is charged per calendar day or part thereof. I was told that parking is only available on the grass. There are different rates for private and commercial aircraft. The rates drop if you stay four or more days, but for three fewer days in a private aircraft they are:
<2,000kg = $26.64 per day
2,000 - <4,000kg = $62.13 per day
4,000 - <5,700kg = $100.61 per day
So for me to fly down in a C172 and stay for a night, it'll cost me 2 x $26.64 = $53.28.
cheers
Jex