But you are in luck. We, the editors of Electric Spec, do work with authors to make stories the best they can be. They don't have to be 100% perfect when you send them in. That should be a bit of a relief for you all. What's the most common thing we do? Besides spelling and grammar issues, we often end up shortening a story. Short stories, in particular, need to be as short as possible to tell the story. :) Yeah, I know, easier said than done.
Speaking of perfection, the awesome writer and writing teacher Kristine Kathryn Rusch, has a really nice article posted on her website: The Business Rusch: Perfection. Ms. Rusch basically says no story is ever perfect to every reader. So, at some point, quit sweating it and send it in! Good advice.
By the way, Ms. Rusch is an excellent resource for writers. Check out her archive of 'On Writing' posts.
Oh, and FYI, we close to submissions for the August 2012 issue on midnight July 15, 2012 (U.S. Mountain Daylight Time). So you still have time to send your story in. :) Good luck.