Although he possesses some of the characteristics of the hero created by Lord Byron in Childe Harold's Pilgrimage, Gatsby is not developed as a classic Byronic hero. For instance, he is not cynical; Gatsby is the most romantic personality Nick Carraway has ever known. He is not tormented by conflicting emotions; after meeting Daisy, Gatsby's life is determined and thereafter ruled by one emotion--the need to experience life again as he had known it for a brief while with Daisy Fay in Louisville, the emotional need to actually repeat the past. Gatsby is motivated by love, and there is no conflict in his feelings for Daisy.
That being said, like classic Byronic heroes, he does reject one particular norm of society at large. By throwing in with Meyer Wolfshiem, he chooses to become a gangster and build his fortune through criminal pursuits. He maintains secrecy in regard to his "business ventures" because they are illegal; they are also socially unacceptable, except to the underworld society that he has joined. In a near-violent confrontation with Gatsby, Tom Buchanan clarifies his criminal activities:
You're one of that bunch that hangs around with Meyer Wolfshiem . . . I found out what your "drug stores" were.
Tom then reveals that Gatsby is a bootlegger and more; he is guilty of violating gambling laws and currently engaged in putting together a criminal enterprise that people are afraid to talk about. Gatsby's reaction to Tom's revelations indicates that the romantic Gatsby is, in some respects, indeed a dangerous man. Nick notices a change in his usually controlled demeanor:
Then I turned back to Gatsby--and was startled at his expression. He looked--and this is said in all contempt for the babbled slander of his garden--as if he had "killed a man." For a moment the set of his face could be described in just that fantastic way.
Nick's observation suggests that beneath the idle party gossip about Gatsby's life there may lie some truth. Making Gatsby dangerous, as well as mysterious, does add elements of the Byronic hero to his character. Furthermore, although Gatsby's life is guided by one primary emotion, to win Daisy back, he does demonstrate conflicting emotions in this scene; his hatred for Tom Buchanan and desire to strike out at him conflicts with his love for Daisy and his need to remain calm and behave in a socially acceptable manner.
In regard to Gatsby's disrespect for "rank and privilege," it can be interpreted in conflicting ways. Gatsby does not reject the social superiority of the upper class. He aspires to become one of the privileged few, buying his way into membership with his wealth and material possessions. However, Gatsby might be seen as disrespecting the rank and privilege of the upper class because he refuses to see it as inviolate; he does not acknowledge that belonging to such a group is beyond him. He has no respect for the social barriers that separate him from Daisy; moreover, he does not recognize their existance.