but you guys have a better healthcare system
Yes we do, but as a non-permanent resident you will be
required to hold private health insurance. Unlike the States, companies in Australia do not provide medical insurance beyond loss of licence and mandatory workplace accident insurance.
Make sure you have a look at the cost of private health insurance without the Medicare Rebate applied, especially if you are over 31 and factor that into your take-home pay.
Unless you have a whole heap of command on a regional turboprop and possibly check and training quals, you will be hard pressed to get a 457 visa. Also, even if you got into QLink, I'm pretty sure your visa will be held by QLink and not Qantas, so there is no way to transfer to Qantas as they do not have approval for 457 visa pilots.