1. I know the flag thing has been addressed, however, unless you intend to include flags from a couple hundred countries, it might be easier to have a "fill in the blank" section. That way if someone can't find their flag, they can at least fill in whatever country they are from. Then, when you have time, you can add the appropriate flag. It just seems to me that would be easier than waiting for someone to mention it in a complaint. If people have a way of just filling in their country even though they don't see their flag, I think they would be more likely to sign up.
2. The background images are lovely, but it is difficult to read. Maybe a nice Twilight banner across the top and then a black background for the rest of the page would be easier on the eyes.
3. Since the site is done in English, I would suggest having a native English speaker on staff. I think your grasp of the English language is wonderful, and I haven't had any trouble figuring out what things mean even when they are mis-spelled. However, having someone around to catch those mistakes first would make the site much more attractive. For instance, on the home page, "summury" should actually be spelled as "summary." Those kind of mistakes make the site look less professional, and correcting them would probably help in showing it is a well-designed legitimate site to attract new members.
I really love what you've done here, and I'd like to see the site grow in membership. Just a few small fixes would probably make a world of difference.