The "Josh" character strikes me as an extreme case of Asperger's Syndrom:
Low self awareness, inability to intuit psychological situations, low empathy, manipulative, ruthless, cunning, flatness of affect but unlike true psychopaths he retains technical skills, is hygienically agnostic, and totally unconcerned with his personal appearance.
Often, when a particular area of the brain does not function well (if at all), other areas of the brain overdevelop -- in an effort to compensate for the missing brain function. His "genius" could stem from that... he could have an IQ as high as 180, but with no grasp of psychological reality, zero team integration, and a truncated worldview... he is virtually worthless.
And thats before you let him log in to your cvs server and create downstream mayhem!!!!