I got a diagnoses of dsm axis 2 personality disorder with features of narcissistic, borderline, ocd, dependent and histrionic. Why such a loose defini?

"Features" only. Key word here is "features" of various personality types. The interviewer noted that you have a fixed pattern of relating to the world and others no matter what the situation (personality disorder). This apparently includes features found in several personality disorders but no definitive one stood out. Firmer delineation may come over time, but characteristics of these disorders may overlap.
Personality do. Wondering if that came from the assessment interview or from psychological testing such as personality inventory or mmpi. What u describe is having feature of those different profiles but no single personality disorder diagnosis. Recommend further inquiry from your doc.