All those 4 things you mentioned got nothing to do with stuttering. No one really knows what causes it, hence there is any cure for it. Anyone who tells you “they can fix” stuttering is a scammer. No meds, surgery, procedures will fix it. Only way I have found to get around the “problem” is masking. Everyone has their own way or has to find their own way to mask it. For me, faking an accent, having a hard candy in my mouth or having cliff notes for meeting works to an extent. Another thing that helped me is to accept the problem and move on with my life.