Re #1: Usually when we say someone specializes in something it refers to their familiarity with a particular subject, skill or other. So yes, I would understand from the context that he is familiar with using these techniques.
#2: Yes, this puzzled me too. From my nursing experience I can guess that it refers to illustrations in the medical field that are not patient-related, but I am only guessing. I have noticed some of your questions are scientific in nature - I was wondering if you have tried other science-based forums more particular to the subjects. Even as native speakers it's not always clear because of unfamiliarity with a subject.
Student or Learner