One thing that seems dangerous is the practice where sanitized/bowlderized versions don't note that they are sanitized or abridged (sometimes significantly) so

One thing that seems dangerous is the practice where sanitized/bowlderized versions don't note that they are sanitized or abridged (sometimes significantly) so the readers think that they have read the classic book but have not really, as critical passages (especially those which are heavy enough to warrant discussion with others) were missing from what they read. Readers have to right to know if they are getting the original or not, so that the choice is informed and not accidental.