I have a little training in script writing, though I haven't finished one myself. Working slowly on that.
Editing is one of the toughest and most heartbreaking parts of moviemaking. It's also one of the most essential. A story I heard once: editor and director are in the cutting room. The editor says, "we should cut that scene." The director desperately fights it at first. He even says, "when I read that scene in the script, that was the moment I knew I could make this picture!" But he resigned that the editor was right. The scene was removed.
It is probably the same in writing. I am going to do my best at keeping my story uncut should it get published.