I think the things you are worrying about now aren't the things you may find difficult if/when you arrive.
QLD has some spectacular storms. Yeppoon was quite badly affected by a cyclone not too long ago. But, you know, weather can affect you wherever you live in the world.
I am shit scared terrified of spiders. There are some pretty bad ones out here, but again there's ways to deal with it. You get your house sprayed and protected, and just use sensible precaution (for example I don't leave my shoes outside). Snakes are pretty much going to leave you alone if you leave them. Kids need to be educated and trained, but plenty of Aussies manage to do just that! Bugs etc can be a nuisance on an evening, use spray/candles/traps etc. The thing that's irritated me the most since I've been here was actually a Bleating Tree Frog. Unsociable little sucker has been screaming in my garden for months, disturbing my sleep. FINALLY found him last week and relocated him to a stream away from my house.
What I found more tricky was the culture shock. Just because it's an English speaking country I just wasn't expecting it to feel so different. I was naive. You do get used to things, but it takes a little while. It also took longer than I thought to really meet and makes friends with people. Again, I thought it'd be like living in Neighbours. Clearly I was an idiot. The lifestyle is great and I think it's a great place for kids, but many people end up moving back becuase they are homesick and miss friends and family. When things go wrong at home you are literally on the other side of the world. You feel so far away, and the time difference really cements that too.
I am jus trying to give you a balanced view though. I've now been here 7 years. I have met and married my partner, bought a house I'd never have been able to equal in the UK, have a well paid job, good close friends and am expecting my first baby. I could never imagine moving back to England. Sadly I have just learnt that my Mum is very sick, and it's very difficult to cope with that from afar.