Hello and welcome. I agree with the comments above. Both @JeffH and @Peter48 are in Queensland too, and both are exceptionally helpful, so they could be an excellent resource for you if they are close by.
I agree with the need to spend time on studying (read and watch youtube, get a mentor etc). After that, building the hive will take you about 2-3 hours, then another couple of hours to seal or paint it.
If you buy a nucleus or one of Jeff’s colonies, it will take you about an hour to install them if you have never done it before, or about 15 minutes if an experienced beekeeper helps.
They will then need time to build up their numbers before you can think about putting the Flow super on for harvesting honey. That will depend on the season and your local microclimate and forage availability. It could be anything from 2 weeks to several months. Only inspections will tell you when they are ready.
I allow about 1 hour per week per hive. As you get more experience, you can do it faster than this, but at the beginning, it may take you much longer.
It depends on what is in the bush. You will need to research that yourself, or tell us where you are located a bit more accurately, so that any locals on the Forum can advise. Some flowers are not very conspicuous, but they are loved by bees. Unless you are willing to plant farmland sized areas of bee friendly plants, you will not be able to feed the hive from only your own property.
I would, especially during a nectar flow. If you don’t look at them every one to two weeks, they have a sneaky tendency to swarm on you, which can take 2/3 or more of the population away from the hive within a few weeks.
Not in a Flow hive, and not if you want decent amounts of honey. Native bee honey is very tasty, but very low quantity and doesn’t keep well. Native stingless bees are too small to use a Langstroth or Flow hive. If you get bees from a reputable supplier, they will usually make sure that they are from a gentle stock. You will still need protective equipment like a suit or jacket, gloves and a smoker.
Depends on what you want to do. You will need the equipment I mentioned above, a hive tool, glass storage jars and a few other bits may come up that you want. I would budget for another $300 to $500, but many of us spend a lot more than this when we really “get the bug” and want to purify wax, have nice labels, etc.
Keep asking questions if you can’t decide. Bees need attentive beekeepers, but they don’t need huge amounts of time, they just need consistency.