Good response. It is an Australian question, and looks like VFR.
I believe most of your analysis is correct, but I also note that the question states non-populous area, and flat terrain, so the low-flying limit then becomes 500 feet. At 500 feet AGL I would be over 3000 feet AMSL, however, by stress of weather, when I am within 1000 feet of the ground and able to see it, I merely have to be clear of cloud, and that rule is in operation above 3000 feet AGL.
So per my understanding of the question, the flight it is allowed.