I just got an Apple TV.

Yes, I know, a new one is just around the corner but my father took it for me for my birthday as a surprise and I'm happy. Anyways, I have some doubts I need answers to -

If I rent movies from iTunes, will they be downloaded or streamed?

How can I play my local files on my Mac on my TV?

What is Plex?

Which airplay apps should I download on my iPad/iPhone?

And finally, how can I use Netflix here in Inida?