Answer 1

You can't. If you did, you would have to either log in, or hack into the server and extract the data. If you have accounts with the website, your scraper could log in for you. There are ways to add usernames and passwords to website requests.
This is the exact problem that created the "deep web." All of the data located behind pay walls and user authentication and private servers is not accessable; thus a deep ocean of information not accessable through many search engines. Some servers allow google special access so that people can find out about their servers, and pay/sign up for their services.