Yes, Redmi Y2 does have the front camera flash.
No. None of the Xiaomi phones comes with the earphone. You have to purchase it separately.
Yes, Redmi Y2 does have the OTG support.
Yes, Redmi Y2 does have the support for Miracast.
The Xiaomi Redmi Y2 is a slightly better attempt at a selfie-focused smartphone than the model it replaces. It has proven hardware that is capable of delivering a smooth user experience, plus MIUI 9.5 which has a lot of added features.