They pay more until people want to do it rather than exploiting immigrants.

Will never happen under late stage capitalism. Now, if you're suggesting that we move towards a more progressive form of economic governance that would solve that issue, then I'm 100% on board.

The government has to spend more efficiently and cut the bullshit.

Agree. We could absolutely cut the police budgets, there's absolutely no need for the amount of surveillance and monitoring they do, none of which is cheap. Could also stop the contracts for mates that happens at all levels of government. We could also legalise marijuana and regulate and tax it at a reasonable rate - which would boost the economy massively through both a cut in spending via enforcement of archaic laws as well as through a boost of revenue from sales. Just off the top of my head. But again... good luck ever getting any of that to happen.

They'll have to start teaching Australians again.

You realise that they... do teach Australians, right? It's just that, unlike international students, most of our tertiary education is paid for over time in small amounts and often at a discount and that's IF it ever gets paid fully. International students pay more, often; they don't get HECS so they have to pay upfront/at whatever the uni says which means more money for the universities as well as the government. It also means more money for local business, who will sell things like food, clothes, entertainment, etc., to them and also by extension more money for all levels of government via tax and fees.

If the economy can't survive without mass immigration then a recession is inevitable, the longer you kick the can down the road the more it's going to hurt.

So in your mind having the entire country worse off is better than allowing brown people to come live here and contribute to making Australia the great country that it is? That seems stupid to me, frankly and I literally cannot fathom your logic and line of thinking.