- 2 hour connection should be sufficient if things are on time (at least on-time by EK standards). You should be off the plane at around 0830-0840. Allow 20 minutes for the walk to and clearance of security. Terminal 3 has 3 concourses, A, B and C. The "A380 concourse" is a bit of misnomer/marketing gimmick. A380s depart from all 3 concourses (although rarely C). You will find that there may be people stopping to check the flight information screens after you disembark: I recommend you skip that and head straight to security and check the screens after security clearance up in the shopping mall/concourses if you want to try and grab some lounge time. If all goes well, you should be in the main terminal at about 0900.

- You will not need to clear customs or immigration as JTXC has mentioned

- There are F lounges in all 3 concourses. Assuming you are out of security at around 0900 you should have some time to grab some food/drink/15 min massage if you like to cut things close/shoe shine if you're in FCL B and it's available as a 1015 departure should be boarding at around 0940-0945. Of course please do look at the screens / listen for announcements in the lounge. If your flight to SYD departs from the same concourse as you end up disembarking to, you are in luck, otherwise it's a train and a walk that will take up about 10-15 minutes of your time depending on the train wait/your walk speed. You can tell which concourse you are in by looking at the A/B/C prefix to gate numbers.

-FCL A can be boarded directly from the lounge. FCL B you may or may not be boarding from the same level as the lounge, but it's not inside as it is in A. FCL C, well, you will be walking :P

Hopefully that has answered any lingering questions!

Enjoy your trip~