Yes, Mi A3 does have the in-display fingerprint scanner.
Yes, Mi A3 does have the IR remote sensor.
Mi A3 has a 6.08 inch Super AMOLED HD Plus display. It offers 1560 x 720 resolution. The display is protected by Corning Gorilla Glass 5. Mi A3 has 19.5:9 aspect ratio. The mobile offers 60000:1 contrast ratio.
No. Since Mi A3 has a drop display, it does not have a notification light.
The Xiaomi Mi A3 will only appeal to people who really value the stock Android experience and software updates, and who want good camera performance, without breaking the bank. For that specific target audience, the Mi A3 is currently the best option there is in the market.
The Mi A3 combines a striking gradient design with decent internals and a clean software interface with the promise of quick updates. The 4030mAh battery easily lasts a day, the Snapdragon 665 chipset ensures there's no lag, and the 3.5mm jack is back.