Great video and pics! It looks like a very pretty area down there.
Sorry to hear about your feet; that's really one of two reasons that I went to hiking in Keen-style sandals with the toebox. The other being that it's Florida, and I'm going to get water in my shoes fairly regularly from the rain if I hike in anything but the dead of "winter". I wanted something that would dry out quickly.
Still, with all of the wildlife down there in Oz that doesn't like humans, I might just go with good, sturdy trail runners and gaiters like everyone's been recommending.
You mentioned a local cobbler. Does (s)he do custom boot manufacture? It might be worth considering, if you still want a boot rather than a Keds-style shoe, trail runner, or sandal. Heck, it might be cheaper than those $400 boots you got at the store.
Don't sweat a 10-kilo base weight. That's about what I run, and as long as you aren't trying to pack through extremely dry areas, it won't kill you. Without going to ultra-lightweight materials for most of your stuff or going to a ground setup, that's pretty durned good. Just make sure you get out with it fairly regularly to ensure you don't lose your back, knee, and ankle support muscles (don't know why I'm saying that; it looks like you get out more than I do, for certain).
Anyway, thanks for the ride-along! It's a wonderful area, from what you've shown us, and you're awfully lucky to be able to get out there!
Also, French nudists? Not something that I'd expect. Funny, though!