Yes. In fact, iTel S41 has ring indicator which blinks when you get a new notification.
Yes, iTel S41 does have VoLTE support.
No. iTel S41 does not gorilla glass but it's display is scratch resistant.
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, It does have.