Most of Australia is safe, although there is places you have to be carefull. Anywhere near water (creeks, rivers, lakes) in Northern Australia has issues with Salt Water Crocodiles… large numbers because they are protected, can grow up to 4-5 meters, very territorial and supremely cunning… most sharks are no match for a clever Croc…
Over on the Pacific Coast off Northern Queensland (Great Barrier Reef) locals generally don’t swim in the ocean because of the Jellyfish and Irukandji swarms at certain times of year, Crocs once again, Bull Sharks and Tiger sharks less so but they are around. The Great White Shark generally only inhabits the cooler Southern Australian waters below the bottom half of the continent.
Australia has a few venomous Spiders, Redback (Very Common) and the Funnel Web which won’t kill you unless you are really young or frail, but will make you mighty sick and their venom can cause permanent tissue damage.
Snakes are all across Australia with the most venomous ones once again found in the hotter tropical northern Australia. I live in the south of the country and even as a kid in outer suburban Melbourne we had a lot of Brown and Tiger Snakes around… They seem to be less common now in the outer suburbs due to the sheer growth and development that has driven them out or killed them off.
I have a hobby farm outside of Melbourne in rugged bushland and most snakes are only seen when pinching eggs (or whole chickens), other wise you don’t see them.
So… It’s pretty safe all over… we don’t have the wolves, bears, big cats and other killer wildlife that are responsible for a lot of fatalities in other parts of the world…
Hope some of you find this of interest… Cheers