"Little Shop is, in some metaphorical way, ABOUT race- more specifically, about the sounds of black music as an "alien" presence in white culture. All the "good" characters are white, but stupid. All the "bad" characters are black, but clever. The white characters, knowingly or unwittingly, are all attempting to make a buck off black culture, which proves too fecund and strong for them to harness and control, and it spreads everywhere.
I don't think it totally fits that reading. The urchins aren't presented as "bad," but rather neutral, omniscient observers. Orin is white, but decidedly presented as "bad." And if you apply that reading- black culture is a destructive, self-serving force.
"...everyone finally shut up, and the audience could enjoy the beginning of the Anatevka Pogram in peace."