1. McGinn shows an amazing confidence in his ability to judge how his acts and emails are interpreted by the intended recipient of these.
2. There is as Jonathan Kramnick pointed out to me on Facebook, something decidedly creepy (in a Frankenstein sense) in the very idea of Genius-Development.
3. McGinn admits to deliberately erasing the lines between the professional and the personal. This is not unique to McGinn in the discipline. As Jason Stanley noted "there is an overly personal and unprofessional aspect to the friendship and socializing in the profession." (This feature of Stanley's comments got lost in subsequent discussion over his views about the prevalence of assortative mating in philosophy.) We are dealing here with a phenomenon that is at the heart of many of the 'culture' problems within professional philosophy.
4. McGinn seems to be admitting to deliberately sexualizing features of his relationship with his PhD Student in the service of pedagogical ends.