I agree with much of what you say. I think we should distinguish speech-planning-difficulty stuttering and execution-type difficulty stuttering. We should distinguish incipient stuttering from developed stuttering (the severe form). They are not the same! >"*Incipient stuttering (the first symptoms of stuttering that appear in early childhood)  is essentially different from developed stuttering. Incipient stuttering usually begins a year or more after a child first starts uttering his first words (Bernstein Ratner; Yairi & Ambrose), and after the child has started to become aware of the need to regulate execution. Stuttering emerges after a period of extensive learning. Children don’t stutter when younger because they haven’t yet developed the language to make speech complex. Typically, stuttering begins around the time that children are putting a few words together in the phase of error-repair. Stuttering onset tends to coincide with critical moments in language development when the child is in the process of acquiring a new syntactic structure or rule. It may begin when the child starts to try to regulate his speech in order to make it more socially appropriate.*"