Yes, Oppo Find X does have the OTG support.
Oppo Find X does have the 6.42 Inch AMOLED display. Do check this video to see how durable is the display of Oppo Find X.
Yes, Oppo Find X does have the USB Type-C jack. But Oppo also provides the USB Type-C to 3.5 mm headphone adapter, so you can use your 3.5 headphones easily.
No. Oppo Find X is not a water-resistant device.
The Oppo Find X is the most unique smartphone money can buy today. And that's enough to tip the scales for a lot of people. By winning the beauty contest Oppo has already secured a best-seller status for its latest flagship.
Its near bezel-less screen, eye-catching rear glass panel, cool pop-up camera mechanism and class-leading battery life make the Oppo Find X one of 2018’s most interesting phones. However, its less-than-stellar camera, restrictive software and eye-watering price leave a bitter aftertaste to what is an otherwise delicious flagship.