Idea threads around the Writer's Lounge usually deal with ideas that haven't been put into production yet, in part because the posters of those kinds of threads are looking for a reaction before actually putting any sort of work into a fic about their idea (just in case it turns out to be something that won't be touched with a ten-foot pole by the community) and in part because a fanfiction that's already been posted can easily get comments on the story thread itself (to avoid making people have to switch back and forth between threads to see how other readers received the piece).
In other words, what you're looking for here is a bunch of reviewers, not feedback on your idea the way the pre-production people (i.e., writers who haven't actually started a fanfiction) do in idea threads in this forum. If that's the case, may I suggest
this thread to help you find reviewers and
this one (if you don't already use it) to advertise your story? Additionally, if you're looking for someone to help you proofread, perhaps you'd benefit from
looking for a beta.
If you're concerned about the fact that you're not getting as many reviews as you'd like, my advice is to be patient. You're a new face around here (one who hasn't even really
participated in the writing community around here to get yourself some exposure), and anyway, people are posting floods of stories, many of which have already unfortunately shoved yours off the first page. Kids tend to gravitate towards fics that are on the first page and are by people whose names they recognize, and sometimes, it's hard to get reviews even then. Use advertising methods like the ones I've linked to above and connect with people who frequent your forum, and that should net you a decent following.
Long story short:
1. You're already posting your fic, so we'll comment about your story on that thread if we want to.
2. The people who post their ideas in idea threads here haven't started writing yet and are looking for feedback before they devote themselves to a concept.
3. There's some good threads (again, linked above) that can help you get the exposure you need for your story. I'd suggest going with them. (Also, try finding a beta if you want someone to help you proofread.)
4. Be patient. Feedback will come to you with some time.