I am a cyclist and obviously drive as well.
I believe the point about cyclists not paying rego is a bit invalid given that the majority of adult cyclists would actually own atleast one car and therefore pay rego anyway and every day you dont drive that vehicle on the road you are helping reduce the maintenance costs to the pavement etc.
I too will ride in a lane through a roundabout for two reasons. One to hopefully be seen by other vehicles entering and also to stop vehicles trying to pass you on the roundabout.
I generally will not ride through a red light with the exception of early morning etc. through turn signals. A bike will not triger the signal so you never get a green arrow. I have seen many cyclists running red lights and almost being cleaned up, as usual its usually the minority that give the group a bad name. A bit the same as 4wding I guess.
Also, the best thing a cyclist can get is lights, but they have to be good quality ones. I run Ayup lights, they are Australian design and made. I run twin lights on the bars, twin lights on the helmet (drivers tend to see you when you shine the head mounted lights straight at them) and a set on the rear with red covers. These lights are visible for atleast 150 - 200m and actually work for lighting your way if there are no street lights.
Anyone that cycles a lot should check them out, there expensive but you can put them in the dishwasher to clean them if you want too.

