I like the idea but I would prefer if the sky took a smaller part of the pic so the main theme would be emphasized. That said, I do like the way the tracks start.
I had a similar thought but when I cropped out more of the sky the picture's balance was off. The darkest part of the sky was at the top and it was necessary to balance the much lighter ground and almost white white gravel under the tracks.
If I shot at a lower angle, I got my shadow in the picture (you can just see it on the gravel right at the bottom).
It came down to a question of what was more important: the photographic quality of the shot or emphasizing the assignment. I went for the photograph because in the end, that's what's more important. I still think it does a good job of showing the assignment. That's why I made the rails so strong, graphically.
I like the expanse of sky. The picture feels very symmetrical: both left and right, as well as top and bottom. Cropping would diminish that. Also, cropping out some of the sky would lose the darkest part--one of the features that makes this image compelling.
I think what you are seeing in the horizon is the curvature caused by the 12mm lens i used. I thought the same thing when I first looked at the picture but, according to the grid in PhotoShop (always my final arbiter), it's level based on the railroad ties.
