Jabs,
Having been involved with a couple of political groups over the years, I would suggest that we will never get traction with an established party due to their own internal politics.
If Abbott pulls an early election as speculated or a Double dissolution, it will be very interesting indeed. We will not have time to get it up through some other party's mechanisms.
...and to illustrate a crack before we even start, I personally don't view the shooters and fishers to be uniformly "common sense".I suspect that you would view my personal political position to be somewhere in the "loony left" spectrum.
A single-issue party (for all the limitations that would bring) keeps it all very neatly and narrowly focussed for the people we are going forth to represent.