1: See, you are a cad. (3)
2: Dizzy Ben is a playwright (5)
3: I bang rock, disturbing snake (4,5)
4: No one told sister (3)
5: Notes spent in Germany (5)
8: In Howard's End - one has a passage here from Forster (5)
9: Odd bits of Niacin and Sprite (5)
11: Bounder beheaded by slippery swimmer (3)
13: Mink, for one, may fly when theres trouble (3)