Computers themselves tend to be made up of many patented components; it is the operating system and software that is protected by copyright.
When you buy software, what you're really paying for is a license to install and run it, generally on a single machine. It's also possible to get bulk licenses for multiple machines, such as at a business or school, and most licenses (embodied in the End User Licensing Agreements) do specify that it is legal to make a backup copy as well.
from copyright clearance center
Yes; but the vast majority of uses would require licenses from the copyright holders.
Public domain images have no copyright restrictions.Creative Commons images are protected by copyright, but have extremely broad licenses.
Yes; most licenses are non-exclusive, limited, and revocable.
You would need to go directly to the rightsholders individually.
Copyright protected or trademark images, such as cartoon characters, require licenses from their owners.
There's really just the one. There are many, many different licenses, though.
Yes, often more than one for each book.
The Copyright Designs and Patents Act defines patents for computer hardware and software, and copyright on software.
No, they only monitor the licenses that come through them.
No, using a cover of a song without copyright for your own performance or recording is not allowed without obtaining the necessary permissions or licenses from the original copyright holder.
License art? If you mean a copyright, you have that for anything you make. If you mean to sign a contract and sell copyright licenses, you have to be 18, or your parents have to sign the agreement.