Would you allow shuffle goals?

Neither of these two points are reasons to change the ruleset in my opinion.

Neither of those two things were the reason I have for allowing them.

My main concern is that it only takes a few baby steps to change things dramatically, I don't think we should view change as a positive thing by default.

Absolutely right. high-five

If you allowed shuffle goals in Australia, the sweeper mallets users would own the court (the style is already akin to ice hockey when watching them play, hence the comparison), why wouldn't future players see this advantage and push for a different standard mallet? Would this be a good/bad thing if the ball was pushed/flung/dumped and why?

We're into hypothetical discussion territory now (not saying that this is a bad thing), and no one knows the answers. But: You're arguing that if we changed the rule now, another rule could be changed in the future? That's quite possible. And if people spontaneously decide that want the game to change, and enough people agree, it will happen. There's no point in fighting it.

I don't understand your second question. Is it: If everyone had Australian sweeper mallets, would it be a good thing (in terms of how they interact with the ball on the court)? If so, my answer is no, I don't think it would be a good thing. But I could be wrong.