I don't want to hijack your thread too much, but you might have some disagreement with people over in the west about BK being Australia's busiest GA airport. They would also have the stats to back them up.
http://www.airservicesaustralia.com/...calytd2005.pdf
Link is to movements for the calendar year to Nov 2005.
Jandakot has significantly more movements and Bankstown is only just ahead of Moorabbin. The other 2 GAAPs, Parafield and Archerfield are well off the pace. As for the relative complexities, that's a whole new ballgame.
Back to your topic - to those GA people who do listen, don't forget that speaking over the radio is just part of the BK ATCs job. They also have to do a significant amount of coordination with the other controllers in the tower and at Sydney. Quite challenging when it gets busy.