Abandonments in Australia have nothing that anything overseas doesn't have. There is still a sense of enjoyment, but when you travel overseas you want to explore what is iconic and optimum to the UE environment of whatever country you chose. Drains in Australia are plentiful, and in case you didn't notice none of us wear waders because the water here isn't
too dirty. I did a road tirp from Brisbane to Cairns once covering about 1300km and we did 8 abandoned buildings... theres just not that many here from the start, and what is here, is not so good.
The legal side is nothing different to the UK, to my knowledge. If you're caught on Crown or Military land you're done for good; permanant criminal history, with refused entry into some overseas countries. If you're busted on Government property its a little intense but usually a slap on the wrist (although these days I am hearing a lot more about police dogs) and depending on how far the owner of a private property wants to take prosecution, you can also get in deep trouble but generally private property abandonments are tame. Exploring rooftops and train tunnels here is a thing of the past these days because of intense terror legalities blah blah blah. The only people who do that are instragram kids.
Where people go, animals run; urban environments scare away wild life. We have typical drain critters; spiders, centipedes, cockroaches, frogs, eels, and bats etc .. but the venomous creatures often live far from the cities. However if you encounter a redback spider, you don't want to anger it. The smaller and more "pretty" the spider, the more poisonous it is. Wasps live in abandonments and can seriously harm you so if you see wasps, run. If you're out in regional towns you might get kangaroos and wombats that can be territorial and aggressive. I rememeber we did this prison surrounded by roos and as we left at sundown the big daddy got really pissed off, and started growling at us. Luckily for us we had torches and scared them away as they circled us, like fire to zombies in Night of the Living Dead.