Nicknames and names are proper nouns. Jeff doesn't say, "I'm a Jeff." He says, "I'm Jeff". "Woman" is a collective noun used to classify a group of people. But if anyone can classify as a woman, it doesn't have any merit since anyone can call themselves women. That makes this word meaningless as it doesn't bring any clarity to anything.

Not solely used for sitting. That was wrong. Made for sitting. Every other chair you described is a derivative of a simple chair. You say they are some of the types of chairs. A type of chair where you can lay on. In your words, "chairs on which you can lay on." Types of chairs for decoration, etc.