Though, Apple has not mentioned on their website about the same, but during our extensive review of the device, we have found that iPhone 8 64GB & 256GB variants does have 2GB of LPDDR4 type RAM.
No. iPhone 8 does not have the FM radio.
Yes, you can play 4K videos on iPhone 8.
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.