What I was getting at with that screenshot, is specifically the gap between the level preview and the title - it won't be filled with black, unless (a) the level actually has black at the bottom (which was the case in the earlier screenshots), or (b) the level is so wide relative to height, that when shrunk to fit, the limiting factor is the preview area's width rather than its height.
Or to describe it more technically - the preview area, which gets blacked out, is 864 x 160. The level image will be resized, keeping aspect ratio (no cropping), so that it's no more than 864px wide and no more than 160px tall. This resized image is drawn, centered, in the blacked out area. More often than not, the level image comes out as 160px tall, and <less than 864px> wide.
Time limit definitely needs to stay on the preview screen. It's rare and significant enough that it should have this kind of attention drawn to it. If we did want to reduce the number of (potential) lines, one option could be to move the author onto the same line as the rank / level number?