Outlining short stories can be useful, especially if you want to have a clear structure and direction. It helps you avoid getting lost in the story. However, if you have a natural flow of ideas and can keep track mentally, you might not need it.
It depends. Sometimes outlining can help organize your thoughts and plot, but it's not mandatory.
Well, it's not a must. Some writers prefer to start writing and let the story unfold naturally. But for others, outlining provides a framework and makes the writing process more smooth and efficient.