Yes the far right have such a grip on power within the party that change is hard to effect. A bad result in Canning should be enough to see the party look for a more capable leader and conversely a good result would see the incompetents maintain control and run against the ALP incompetents at the next election.
The green vote is at an all time high in a recent poll, from memory 17/19 percent. If the status quo is maintained in the big two party's i would expect it to continue rising as long as the pragmatic new leader dominates policy formulation. The two majors are just so putrid and have been for quite some time now.
