Yes, Redmi Y2 does have a dedicated MicroSD card slot. You can use 2 sim cards and a memory card at the same time.
No. None of the Xiaomi phones comes with the earphone. You have to purchase it separately.
Yes, Redmi Y2 does have the front camera flash.
No. Redmi Y2 can support only one sim card on 4G network at a time. Another sim card will be either on 2G or 3G network.
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.