Christmas cruises are not really my thing especially in Asia, we had all the rush and hurry of Xmas prior as we were being away without any of the best things at Xmas which was being with family. If we do it again we will definitely have all the family with us.
The fines for bringing a cat onto a ship can be severe as demonstrated in Red Dwarf.
Dave Lister (Craig Charles), preserved because he is in suspended animation as punishment for bringing a pregnant cat on board illegally. The shipboard AI, Holly, sets a course out of the solar system, planning to release Lister from stasis once the radiation from the leak drops to a safe level.
Three million years go by.
I haven't overnighterd on board in Sydney but have elsewhere, there was no curfew but obviously a reduced staff and security to get back aboard after 11pm.
As for the quay area at night, it is not that loud but you do get some sound that travels over the water and also down from the rocks. I doubt you would hear it from your cabin though.
I am not that familiar with Xmas cruises as I have only done one and it was through Asia, so there was nothing Xmasy except for the peoples choir.
Being a domestic cruise, there may well be more.
BTW, there is a ACT Cruisers group that meets every second Saturday, at the Yacht club, 3pm.