No. iTel S41 does not gorilla glass but it's display is scratch resistant.
Yes, iTel S41 does have the eye protection mode which reduces strain for long reading.
Yes, It does have.
Yes, you can use 2 different WhatsApp accounts in iTel S41. Not only that, you can use 2 different Facebook, Instagram and Twitter accounts as well.
Yes, iTel S41 does have the LED flash with the front camera.