Yes it does.
No, you'll have to purchase a USB microphone.
Apple makes a range of Mac computers. Most of them include a built-in microphone.
Mac Mail or just Mail as Apple refers to it comes preinstalled on all Apple Computers.
Most desktops come with a built in screen (all in one piece) but if you get a Mac Mini, which doesn't have a built in screen, you can use any monitor, it doesn't have to be Apple.
Apple has headphones that have built in volume control and a microphone. I have them. You can probably get them at Best Buy for forty dollars
Apple wanted to be the software, and hardware company. That way Mac OS X is built for the Mac computers.
Yes, the newer Apple laptops have built in iSight and can be easily used with Skype.
apple microphone
To install Apple's Mac OS X you agree to only use it on hardware built by Apple and so it is illegal to use it on other platforms.
April 1st, 1976 Apple released the Apple I (and started Apple computers). They were hand built by Steve Wozniak and first shown in California to Homebrew computer club, so I presume they were built there.
Yes, it does have a microphone, as well as a built in webcam.
Yes you can get Minecraft on an Apple Mac.