In the official packaging of Nokia 8.1 - you will get your Nokia 8.1, USB Type C cable, Power adapter, Headset, Quick start guide & SIM door key.
No. Nokia 8.1 is not a water-resistant phone.
Yes, Nokia 8.1 comes with headphone in the box.
Yes, Nokia 8.1 does support Qualcomm Quick Charge. It also comes with 18W fast charger.