Hello steemers! a newcomer has some questions

Hello Steemers! I'm a newcomer having some questions about steem.

It would be greatly appreciated if you help and make this post a guide for newcomers

1. How many STEEM coins get generated a year?

2. how much do you get paid for your SP every week?

3. where does the contents get saved? Does steam have a server?

4. what happened on 4Jul16?

Thanks