+ 1 the idea of a way to see the cropped result. This would be especially useful when doing a significant rotation, as I find the rotation of the crop (vs the photo behind it) to be less than idea in terms of visualization. I realize that sounds silly because, well, it's RIGHT THERE and you can see it, but it's not. A quick keyboard shortcut or button to go full screen as a preview would be very nice there.
While we're picking on crops, I sure wish the crop overlay had a fine grid. Often the vertical lines I want to align with are nowhere near the marks on the crop, involving guessing or moving it over, rotate, move it back. Just a bit more fine, not overboard, maybe a light grid between each?
My entire use of PM is for import, cull, crop and straighten, so I probably spend 75% of my time in actual use with the crop overlay. I love that it's faster than lightroom (which is why I use it), but it's a bit dinky as well.