No. New Nokia 6 (2018) is not a waterproof mobile phone.
Yes, Nokia 6.1 (2018) does have the Corning Gorilla Glass 3 protection.
No. Nokia 6.1 (2018) does not have the autofocus in the front camera. It has fixed focus camera as selfie camera.
Yes, Nokia 6 (2018) does have the Corning Gorilla Glass 3 protection. You can check this video, which is about Nokia 6 screen scratch test.
At the end of the day, the Nokia 6.1 (2018) brings some welcome improvements over its predecessor.