The blue bottles hang around in the more tropical waters, and only at certain times of the year
Lizards can't hurt you, they're really cute actually, I've got a resident blue tongue lizard in my feed room that is about 20cm long. He just sits and watches me make up feeds and I give him a bit of carrot and some pellets
Spiders, we've got a few nasty ones, the red backs are pretty bad. But I'm still alive and kicking, have yet to be hospitalised or even made sick by a spider!
The sharks, well.... we have a fair few of those I'll admit! Particularly in South Australia and Western Australia I believe. We get some very large great whites, 6 foot is not uncommon. But generally they won't touch you. A handful of surfers will get taken each year, but compared to how many get killed coming off a horse or in a car accident, it's pretty minimal

You did forget the salt water crocodiles though! Now those ones are nasty ******s, in Darwin you can't even swim in the ocean because they all hang out at the beach. There have been a lot of people taken by crocs :/
We have no large, land predators though like you guys!
Yep, it's BLOODY hot!!!! However - I much prefer summer to winter and it doesn't even snow here. And daylight savings is so brilliant, I can go and feed the nags at 8pm when it's cooled down, and its still daylight!
-2c.... brrrrrrrrr no thank you!!!! The lowest it gets where I am in the middle of winter is around 4c and thats at night. During the day, you are really unlucky to be under 13c! Right now it's a quite nice 37c, air condition is pumping, and I am sitting on my balcony under a shade cloth, with a Southern Comfort and Lemonade with ice in one hand, my laptop in front of my and my latest drawing on the go.
Bliss