As director, writer and star, Marianna Palka has come up with a creative, provocative concept with “Bitch”: She plays an overwhelmed, underappreciated wife and mother who snaps one day and starts living life as a dog. But Palka has trouble balancing dark comedy with dire melodrama, struggling to find the right tone as she blend so many wildly different and difficult kinds of movie at once. My RogerEbert.com review.