1. Yes, it's a download, unless your like me and use a usb stick to scab a copy of someone elses minecraft (although, they paid...)
2. Yes, it is free, but you don't get everything with the free version. I think I might actually have a few extra's because I'm scabbing of a paying person minecraft...
3. No, not as far as i know, no one has complained.
4. there is no aim of the game. You run around mining and building and surviving XD It's very fun. And running from monsters too XD