Night visual approach requirements
The requirement to be inside the circling area at night may be unique to Australia. I cannot recall it being in force in any other country in which I am licensed. Here is a fair use copy from the ICAO regs in the Jepp WWT:
Visual Approach 6.5.3.1 Subject to the conditions in 6.5.3.3, clearance for an IFR flight to execute a visual approach may be requested by a flight crew or initiated by the controller. In the latter case, the concurrence of the flight crew shall be required. 6.5.3.3 An IFR flight may be cleared to execute a visual approach provided that the pilot can maintain visual reference to the terrain and;
a. the reported ceiling is at or above the level of the beginning of the initial approach segment for the aircraft so cleared; or
b. the pilot reports at the level of the beginning of the initial approach segment or at any time during the instrument approach procedure that the meteorological conditions are such that with reasonable assurance a visual approach and landing can be completed.
6.5.3.4 Separation shall be provided between an aircraft cleared to execute a visual approach and other arriving and departing aircraft. 6.5.3.5 For successive visual approaches, separation shall be maintained by the controller until the pilot of a succeeding aircraft reports having the preceding aircraft in sight. The aircraft shall then be instructed to follow and maintain own separation from the preceding aircraft. Etc...