I'd go one of two ways. Either put the interviewer as the artist, with "Interview of Firstname Lastname" as the track title, or the interviewee as the artist for all three, with "Interview (by Firstname Lastname)" as the track. I'd likely go for the latter.
Album artist should be the interviewee. Composer should be blank. Actually, I never use either of these two fields, but that is what I'd go with.