Yes, they do. A person may be a good creator of characters, of settings, of situations, and of dialogues, and having the four abilities, produce a full original novel. Another person might be good at three, two or one of the four, and therefore unable to exercise his creativity except by means of appropriating respectively one, two or three of those from another artist.
No, they don't. Remember, copyright protects the exact expression of ideas, not the ideas themselves. So you can create a comic with a Mickey Mouse-ish type character, as long as he does not look too similar to Mickey Mouse. And that's exactly what creators of content do. They steal a lot of ideas from other copyrighted content. And it's perfectly legal until the day comes when those ideas are themselves protected.
Do you pay monthly royalties to the artist who painted your living room? No? Why?
LOL, what a retarded argument. There's no royalties because that's menial work, not creative work. Maybe you can't tell the difference because you've never done creative work in your life. And royalties are paid only once per sale. So I'm only paying once if I buy a painting from the copyright owner and Apple pays only 70 cents to the copyright owner for each song sold on iTunes.