Yes, we had to do a credit card deposit - they were very clear about it, and charges were reversed no problem after checkout. We booked via a different website and I can't recall if we were required to confirm but I wouldn't worry too much about it. If you REALLY want to contact them, I found this email in my records: sales AT megaboomhotel PERIOD com PERIOD au (sorry, TripAdvisor won't let me post the actual email). Credit card surcharges are unfortunately quite common in Australia. You just have to suck it up if you want to charge by credit card (we noticed that in some cases restaurant bills would clearly label the surcharge, and in some cases we paid one amount and then the surcharge was added so the credit card charge was higher!!!).

How early? The front desk staff is not available before 7-7.30 in the morning. You cannot enter the hotel premises unless you have the e key. Suggest you call the hotel and find out. Otherwise you may be in a spot. Of course there is a cafeteria across the road that opens early only on a weekday (office working day). You probably can wait there.