Yes, Nokia 8.1 display works as a flash under low-light conditions.
Yes, Nokia 8.1 does support Qualcomm Quick Charge. It also comes with 18W fast charger.
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.
Nokia 8.1 comes with the Android Pie out of the box. You will also get Android updates for the next 2 years.