iPhone 8 does support fast charging. Apple iPhone fast charges up to 50 percent in 30 minutes when you use an Apple USB-C to Lightning cable and one of these adapters: Apple 29W, 61W, or 87W USB-C Power Adapter.
Yes, you can use the old AirPods with the new iPhone 8.
Yes, Apple iPhone 8 does have the VoLTE support.
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.
We are extremely sorry to inform you that we do not ship the products outside India. Further, we also suggest you buy it from Singapore only so that you can get the warranty for the product. Only Apple iPhone X comes with the international warranty.
No longer the gold standard, the iPhone 8 is still all the phone you need.