I tend to agree with you, but only that ADULT ADD is probably misdiagnosed in adults because it is an easy conclusion to reach without delving too deeply into the person's personality. And when asked specific questions regarding childhood, that diagnosis is reached because the person mentions a slight learning disability, which was probably never a 'disability' in the first place.
Poster's problems can be overcome with particular discipline, and as you say, as soon as an interest and a direction is developed, then everything falls into place.
Ti ck