1. If NSW is anything like VIC then Legal Aid won't come to the party unless (1) you're a minor, (2) you're homeless, or (3) you're poor and you've been charged with something that may result in prison time. I don't think this fits any of the above.
2. Ouch, your insurance is going to
hate you if it turns out they have to cough up for 6 cars... it will depend on how many cars you pushed into each other.
3. I wouldn't bother fighting the fine, it's an assumed thing that if you rear end the car in front in these situations that you obviously failed to leave adequate room to brake. Sorry
Really feel for you mate, as it could happen to anyone at any time, safe braking distance or not.

ZXR750 -> ZX7R. It's an addiction, I tell you.