Black Duck wont close. The hardcore riders start those rumours to discourage people to go there and get the tracks to themselves.
I ride too, I have a CRF 450R, 08 model. I usually go to Black Duck, or Motocross mountain is cool too at Yarraman, I like it more than Blackduck. Ive heard there's good riding up at Beerburrum in the forest, they let you ride their nowadays, as long as you stay off the public roads.
My best trick is not crashing. I dig hillclimbs and trails the most.