I don't mind if you agree or not WarpfactorZ, it looks like whats left of a floor to me and it is in line with the idea of 4 floors in the saucer rim as many here have shown.
The area exposed by the damage is far too large (height) an area to be just one floor, whether you like it or not.
You can clearly see a single corridor through that hole. The three rows of rectangles in the circular hall is unmistakable, and as the ship pans by in the film, it is plain as day. I don't know what else to tell you.
I know you have latched onto the 1 or 2 levels in the saucer rim to back up your idea that the ship is still only 300m long or so, we saw in the promotional media before the first films release that there are more than that.
At the end of the day I would have been fine if the ship had been the same size as the TOS version but it clearly is not, I don't know what else to tell you.