By the time I got her feathers smoothed and her goodies into a bag – she gives me a little snort in passing, if she'd been born at the right time they would have burned her over in Salem […] (2)
We can infer that Sammy believes that it's OK to think terrible things about people in the privacy of their own minds, but they should still be treated politely, even when they are rude to us. (With the Salem reference, he is comparing the customer to a witch.)
She was the queen. She kind of led them, the other two peeking around and making their shoulders round. She didn't look around, not this queen, she just walked straight on slowly, on these long white prima donna legs. (2)
Sammy is drawn to Queenie's self-confidence and pride. By daring to wear her bathing suit into the store instead of changing or putting something on over it, she is showing the courage of her convictions.
"We are decent," Queenie says suddenly […]. (18)
Queenie believes in standing up for herself, even when an authority figure is challenging her. She does this while maintaining her dignity.
"I said I quit." (24)
By quitting, Sammy is attempting to defend the girls' principles and define his own. His act requires courage and daring.
"You didn't have to embarrass them."
"It was they who were embarrassing us." (26-27)
This exchange between Sammy and Lengel shows their conflicting principles. Lengel sees the girls as being disrespectful and thinks they are purposely violating the established order just to make mischief. Sammy, however, doesn't think it's right to behave rudely.