Yes, Oppo R17 Pro does have the in-display fingerprint scanner. Besides, it also supports face-unlock.
As of now, Oppo has not announced any support for 5G network on Oppo R17 Pro.
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 Qualcomm Adreno 616 GPU.
No. Oppo R17 Pro does not have the LED flash at the front camera. Its display works as a flash in low-light conditions.
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.