I'm college-educated with degrees in English and business, so grammar is easy for me to do. I've been complimented several times on my use of settings and dialogue in my stories, so my emphasis is usually on helping others develop in that area. I won't take a story away from you - but will make suggestions as to how I think that YOU might make it better. I'll edit any category...a good story is a good story, regardless of subject. I think that anything that is handled right, and written well, can be made interesting. I tend to focus more on the structural aspects of editing, but don't mind the grammatical/spelling stuff at all.