Further character identification: "Drinking Kid" (Jacob Price) in the credits is identified as Patterson in the show. Sonny's last name is given as Mazerowski.
Unseen characters: Mr. Boudreaux, the school janitor that Matt does an imitation of; Denise Palmer, a girl Gordo mentions that Ethan liked. And of course Kate Sanders is mentioned also.
Characters with no lines: One of Matt's customers, a girl he refers to as "Sunshine."