I don't really know. It could vary depending on the artistic style and the intentions of the comic's author. You might need to do some in-depth research or check with the comic's fan community for a clear answer.
Sure. Well, comics often tell stories through a combination of pictures and text. For example, superhero comics like those of Superman usually start with the origin story. He's from the planet Krypton, sent to Earth as a baby. Then the comics show his growth on Earth, his discovery of his powers, and how he decides to use them for good. He faces various villains like Lex Luthor who try to defeat him. Each issue of the comic is like a chapter in the overall story, gradually building the character and the world around him.
The Invincible comics don't have nudity. They adhere to a standard of presenting exciting plots and engaging characters without including such elements.
The Invincible comics are finished. There's no more new content coming out in the comic series. But you can still enjoy the existing issues and re-read them for a great experience.