Good idea. The only problem would be getting enough plebs to take part.

Hopeless main parties that cannot speak the truth, that being that Australia is ..cked, so i expect the independent to win Farrer ahead of One Nation.

Good idea but your suggestion "local voters could also register as party supporters for a modest administrative fee and help choose the party's candidate" is open to rorting, not just by party power brokers but by other political parties having fake supporters sign up. To stop these two eventualities, community members would need to become full paid up members of the party and would need to be a member for at least 12 months before being able to vote. They'd also need to declare they are not an existing member of any other political party.
But overall, the concept of community priorities has great merit.

WTF?

The two major political parties have had their core membership hollowed out over the last 30 years or so.

The relentless attacks against unions over many years depleted the Labor ranks.

Then with Morrison and in his wake Dutton going all-in on Trumpisms the more reasonable Liberal voters looked elsewhere.

You only have to travel through FNQ and see the dying towns and 1970s infrastructure to see how useless a local independent member with over 50 years of state and federal representation can be.

The cult of personality tends to bring out single issue parties and independents but they don't really add very much apart from leaking more Liberal votes.

I think Morrison and Dutton caused so much damage to the Liberal Party that their more reasonable supporters have moved away and the crazier ones are looking for personalities and single issue parties.

It's not the selection process that needs to change but the policies.

Even the catch phase "Liberals are the better money managers" holds no weight anymore.

At the moment the Liberal Party is on the verge of irrelevance. Using the talking heads on Sky News as a basis for building policy will continue to fail the "reasonability test".

WTF?
I can only speak for what's happened here in WA and I can assure you Scott Morrison had nothing to do with the lay party's problems. The state party's constitution protects powerbrokers and it was/is people like Noel Crichton-Brown and more recently Peter Collier and Nick Goiran who discouraged lay members from signing up unless they were certain to vote in support of the powerbrokers. So to reform the Liberal Party (at least here in WA) requires a major rewrite of its constitution to not just allow community voting but to remove the power of the powerborkers.