Q1: What is “black-oriented”?
She should be 'into' black culture & like black men (ie. Stevie!)
Q2: What is “cookin' at both ends”?
Guessing here - but she should be blessed in both 'areas' , cookin', smokin', red hot, highly sexually attractive (to Stevie) breasts & backside! - (both sides)
Q3: What is “The hand is certainly on the heart here”?
Swearing an oath - hand placed over heart - you are guaranteed the truth & with all honesty.
Just incase: Heart on sleeve - wearing your heart on your sleeve is showing your emotions openly.