Yes, Honor 8 does have LTPS Scratch Resistant (Low Temperature PolySilicon) glass, which is even better than gorilla glass.
Yes, considering the display size and battery capacity, Honor 8 is quite light weight. It weighs just about 153 grams.
Yes, Honor 8 supports VoLTE. You need to update the software, though.
Honor 8 is single sim mobile phone.