Notch does a lot of things, so we have to give him time.
NPCs were added in 1.8 you now don't need mods!
Hard to say as they are randomly generated.
I would say minecraft
List of NPCS: Zombies, skeletons, creepers, enderman, silverfish, squid, spiders. And the most rare out of all of them: The spider jockey.
Only if your world is a server, and people know your world's ip address. As of Minecraft 1.8 there are NPC villages where bots "Live" in your world. However, the NPCs themselves have not yet been added, but will be an update in the near-future.
Maybe in minecraft 1.5.3
It order to add java scripts you have to import them at the start of the page. Writing <script src="location of js">, will make the scripts into the web page.
He never was. He's a Minecraft urban legend.
No not yet. There will be once its updated though
they just added bats.
I wish I remembered
An NPC village really has no useful purpose. It is mainly for looks and so you can interact in fun ways with the NPCs, such as using them to trigger and/or test traps.