i think the rating system is a good idea! Writters can send their stories KNOWING they will be reviewed. And you put them into different classes, like "newbie" "regular" and "expirianced".
Then you rate things, like realisticness, plot, entertainment value, re-read value (this is rating on once you read the story, would you want to read it again?), and i'm sure youcan come up with some others.
You'd rate the newbies with some ease, rate the regulars with semi-ease, and expirianced writters get no ease. I think this would help newbies gain confidence, and when they read their review, it would cntain GOOD AND BAD things about the story! This way, the writter will know what he/she did right, and what he/she did wrong.
I think it shouldn't be reviewed by ONE person, rather a team of 5. All giving the different catagorys different scores, and giving their own overall score, and then the 5 overall scores are averaged, and thats the final score. So, you get a final score, then a breakdown from each reviewer, and then a breakdown of each catagory from each reviewer. I think this sounds fair.
I actually like this idea. It could help people figure out which stories are worth reading, and with ones to skip over.
Oh, you should also break the stories into two catagories, sexual, and non-sexual. That way if someone comes to the site, and wants to read a sexual story, they don't end up with a story about a guy tickling his cousin, or his mom. You should also break the catagories into real stories, and fiction.