Automatically phone getting off while seeing videos in instagram please remove this issue.
Check with other phones u have
Yes flashlight is not at all good
Update your whatsapp
It is like that bro it will be began like after reboot
What's ur camera version now
On all bluetooth headset options in the ringtone and volume area
Try it on settings
Go to a a official OnePlus service center
Go to settings and select about phone and then select android version and there Google Play update and select it and update.
I think it is the light of finger print scanner
Turn off auto unlock
It will be in applications
Go to OnePlus service center near you