It's clear that Stu wasn't the brains of the operations, but he was tall and strong, which helped him during the elaborate Woodsboro murders.
Unfortunately, Cotton and his girlfriend are killed in the opening scene of Scream 3 by a new Ghostface killer who uses a voice changer to confuse Cotton and his girlfriend.
Gale would return and survive the events of Scream 2, Scream 3, Scream 4, and she's returning in movie.