No. You can not record slow-motion video with Redmi Y2.
Redmi Y2 comes with a 2A output charger in the box.
Yes, Redmi Y2 does have a dedicated MicroSD card slot. You can use 2 sim cards and a memory card at the same time.
Yes, Redmi Y2 does have the IR blaster.
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.