That is a beautiful description of the writing process. Only it works a little differently for me. I never have a great first line. Often re-write the first line after the story is done. And I usually cannot write a single word until I have the entire story in my head (do add scenes, but never change where it is going and the broad outlines). Part of the reason why I do not take well to the Beta process. For me it is always, "What do you mean dump the first part? That's like ripping my heart out?" The exception to that is when I have tried to write a quickie vignette and a Beta has convinced me it should be a short story. I have a few of those.