I love the trader ratings idea, it's great to be able to see what other people thought of business transactions with a person, and it's easier to trust someone with a good history. So, props on that.
The only gripe I have is that the amount of text you can type for a "review" is obviously limited, which you can see whenever you check on what you wrote for someone and it got cut off somewhere. It's kind of annoying cause there's no indication that there's a limit when you're writing the comment.
You can avoid this problem by setting a text input limit on the reviewing form that is the same as the amount of text that the final entry is allowed to have. That way, people will know when they wrote too much, cause it won't let them type anymore.