“The Noda B’Yehuda says that there is no issue of tzar balei chayim”
He says that killing is not tzar ba’alei chaim and that ?? ??? ??? ?? ???? ????? ??? ??? ???? ?????. That is not quite a blanket heter.
“And hunting for skins would probably be mutar if you could mitigate sakana.
Your assumption is wholly incorrect.”
If hunting for skins is necessary for parnassa then it would be muttar even if you couldn’t mitigate the sakanna.