Could a person be a narcissistic psychopath? i know someone that fits perfectly! scary!

Yes !,: Personality traits and not disorders can be observed and seen in people on daily basis, so someone may show some traits of narcissism or psychopathy or both. However, making a diagnosis of a personality disorder along these lines, requires careful assessment and sometimes follow up over time before that judgment can be made.

Yes, in a way: Dr. Erich fromm was first to use the term "malignant narcissism"; dr. Otto kernberg discussed it also. http://www.hdbp.org/psychiatria_danubina/pdf/dnb_vol22_no3/dnb_vol22_no3_392.pdf it describes a person who has a core narcissistic personality d/o, and also has antisocial behavior, sadism, and paranoid features. One needs thorough professional evaluation before diagnosis though.

Yes: Kernberg's theory is that psychopaths are extreme narcissists. So, your observation is good!

Yes: Psychopathy (AKA antisocial personality disorder) can often present comorbidly with narcissistic traits in some people. These people tend not to do at all well in therapy, and delight in manipulating the system to their advantage.