A much safer alternative would be circumnavigating Australia. By land via Highway 1 (the world's longest continuous road at 15,000 km). Or by sea in a luxury super yacht ;)
https://www.roadscholar.org/find-an-adventure/21421/circumna...
https://www.roadscholar.org/find-an-adventure/21421/circumna...
If I really wanted to understand Africa I'd pick a city and go work and live in it... Not drive through it in an army truck.
A normal clean toilet is no danger, same as everywhere else in the world, but if you're going to the loo in one of those ramshackle open-to-the-elements rustic outhouses, you might want to check the seat.
Yes, the toxicity on paper of Australia's animals is sky-high, but that's not the full story. You're far more at risk of heatstroke than animal problems when travelling Australia.