Who is Richard Throckett Straker from 'Salem's Lot and what is their importance?

Richard Throckett Straker is Barlow's tall, suit-wearing servant, business partner, and possibly his lover. He is a human, and he is evil. People describe Richard as an older man, outwardly courtly, gracious, helpful, charming, and sexually attractive. He is also described as being "a dandy dresser, extremely graceful, and totally bald." Not everyone, however, is fooled by his charms.