Doubt about AirPlaying to Apple TV

Actually, I live in India. I've not yet bought an Apple TV and going to buy an Apple TV soon.

So, before buying, I had some questions.

1. What about Amazon Prime Videos app? Is it available in the tvOS App Store?

2. Is it possible to AirPlay from a Mac or iPhone signed into a different AppleID than the one to which Apple TV is linked?

3. Does it work on Mobile HotSpot? I get speed of around 3~5 MBPS.

4. Is it possible to use iPhone signed into different AppleID as Apple TV Remote using TV Remote App on the App Store?

5. Does AirPlay require Internet connectivity or WiFi is just for connecting Apple TV with the AirPlay Sending device?

6. Is it possible to AirPlay Videos in YouTube Offline and/or Amazon Prime Videos offline? Can I stream them without Internet? I can have WiFi connectivity, but, is it possible without Internet?!

Please answer my questions...

Thank You in advance...