Back when I used RYM around a decade ago, they had a tool that let you crop and rotate uploaded images within your browser. The tool let you get very precise when trimming the edges, with a button that let you move an edge a pixel at a time. This was very useful, especially when you were dealing with low res photos you pulled off an old blogspot. I think MB would benefit from having something similar.

(sorry if this better for the CAA issues)