Yes, Oppo R17 Pro has a dedicated 3D camera at the rear.
No. Oppo R17 Pro does not carry any kind of IP ratings. So, certainly, this phone is not a waterproof mobile phone.
Yes, Oppo R17 Pro does have the GPS support.
No. Oppo R17 Pro does not have the LED flash at the front camera. Its display works as a flash in low-light conditions.
No. Oppo R17 does not have the 3.5 mm headphone jack. You need to use the USB type C supported earphone. You will get one in-side the box.
Oppo R17 Pro has a lot of points going in its favour like excellent set of cameras, great display and design as well as top-notch performance. I think Oppo R17 Pro can give solid competition to OnePlus 6T going by the overall performance.