Re: Paypal - When asking for more docs and info?
Generally speaking, they will start asking for documents once the volume of transactions starts getting large. If you're just sending $50 here and there, they wont' ask, but if you start receiving thousands of dollars, then they'll start asking.
Also if they ever limit your account for any reason, they may ask for scans to unlock it. Overall, never store any money in your Paypal account, as you never know when you'll be permanently locked out.