1 No
2 Yes
3 You initially.
You are entitled to quite enjoyment of your lot. That you are not getting it is a serious matter. If you can’t get a resolution with the upstairs owner, then certainly take it to NCAT.
In order to prove your case you need expert witnesses. The carpet layer nor the SM are not experts in noise. You need to hire the expert, but the cost can be recovered when you win the case.
The legal argument revolves around the fact that you can’t get quite enjoyment, not what type of underlay is installed.
Additionally keep a diary noting when the noise occurs and take recordings of the noise.
Good luck