No. Vivo Y83 does not have the particular LED flash for the front camera but it does have the display screen flash for the front camera.
Yes, Vivo Y83 does have the AI Face Beauty which detects gender, age, skin tone, skin texture and lighting environment and applies the necessary corrections on your selfies. You also have the option to in-active it.
No. Vivo Y83 does not have the NFC support.
Yes, Vivo Y83 does have the power saving mode.