Pretty sure the point of the previews section is to test out your ideas and get feedback on them, though it often just gets used as a story area.
Want to go more in depth about the story and plot line? Just saying it's a crossover doesn't give us much information to go off of. It could be any from Zelretch switching Rin and Hermione to a passionate, torrid love affair between Harry and Shiro as the world dies and the TYPES begin to move.
So yeah, more data is needed.
fanfiction.net has a beta option, if that's all your looking for, just throwing it out there.
