I am very surprised that you got no response from the RAA, they usually reply within an hour or two for questions like this.
Approval to operate over built up areas is given based on approved engine type, such as Rotax 4 stroke, Jabiru, Lycoming etc. Same as GA world, approval is also given if required but can also have some restrictions like "avoid populous areas to the greatest extent possible."
Why not go GA? Register as a member of GA, no $165 annual membership fee, no $220 initial rego and no $110 yearly rego fee plus you get letters on the side and you could fly at night if you wanted.