The woman that cries in the beginning because of the lyrics Paperboi got in his songs is a reference to the woman who criticized and cried when she saw the lyrics for Norf Norf by Vince Staples
"Caught red-handed" is a phrase of Scottish origin, circa 15th century, alluding to being caught with the victim's blood on your hands either in the act of, or after a murder or poaching.
"Caught red-handed" is not a slur against native Americans. It comes from Northern Ireland in the province of Ulster.
The man showing his gun to Earn has committed the crime of brandishing, a felony in Georgia, but the prim and proper cashier doesn't seem to notice it or contact the police.
Hen is short for Hennessy Cognac.