Yes, iPhone 8 does have Dolby Digital & Noise Cancellation.
No. iPhone 8 does not have the FM radio.
Yes, you can use the old AirPods with the new iPhone 8.
Though Apple never mentioned the battery capacity on their website, during our review of the device we found that iPhone 8 does have 1821 mAh Li-Ion battery.
No longer the gold standard, the iPhone 8 is still all the phone you need.