My suggestion is a key press (such as E) that would allow scrapbookers and image moderators to go directly to the image edit page might be helpful. It's not a huge idea, but it'd be simple to implement (or so I assume), and would help shave off a bit of time, which adds up when you get into editing hundreds of images. With R instantly bringing you to a random image, it just kinda makes sense, at least to me, to have a button to jump to editing image metadata.
(inb4 so what are you going to do with those 3 extra seconds you saved)