I don't think so - but even if you could - you'd have to pay it back in ~30 days anyway as its a charge card not a credit card
Ah so you mean balance transfer from NAB to Amex? Your question implied the other way round.
I don't see that would be an issue at all
"out of Platinum Charge Card" seems pretty clear to me. You seem to be the one with the confusion about direction.
Some T&Cs say that charge cards aren't allowed, but I haven't encountered a problem in practice with Westpac, NAB, or Citibank.