This is a real devil today ... stuck on a few in the top lh corner:
1a Horrible stranger's second sin (10) ????s???s?
9a projecting part, large on e attached to a plant (7) ????l??
12a fight back, restricting opening of secret files (5) ????s
1d swallow in group coming north over spain with speed (8) ??????t?
2d surprised to get exhausted after a mile (8) ??????e?
16d disagreement's very bad in a race (8) ?a?i?r?e