Hi welcome to Cruise Critic,
There should be an Aussie power point in your cabin by the desk, as well as a US one. There should be a few USB ports as well.
It depends on the powerboard, generally one's with surge protection will not be allowed.
See the Maitre de and get your bookings aligned so that you are seated together, however if you show up together to eat at any of the restaurants, both room numbers will be asked for any way.
For tours, you will need to book both cabins in for the same time on the same shorexs and show up at the theatre at the same time to ensure the same group number tickets.
As for the roll call for your cruise, there may not be one but check here
https://boards.cruisecritic.com.au/forum/2470-pacific-adventure-roll-calls/