Hey Corran, CTRL+ALT+PRINTSCRN? What decade is it again? Anyone willing to go through three steps to pirate a file would learn to cut one out by using the Snipping Tool (which I do quite a bit to generate training materials). 🙂
But I think you might be seeing the trees and not a forest. Disabling right-click downloads actually does have a meaningful effect - because that's the function that allows you to pull down an entire file from a web server, as it exists on the source, and not lose any quality through recompression along the way when you subsequently turn it into a JPG or GIF for misuse. Screen shooting is markedly inferior for photos due to the way that web browsers (and some services like Facebook) resize, recompress, or re-colorspace the material (look at how Facebook butchers b/w photos).
There will obviously never be a complete inhibitor to copying digital material (just as you can highjack and record audio streams), but it is certainly possible to make it more inconvenient. The scenario you describe - to screen shoot, cut, paste, crop, and re-save is a ton more effort (for a lot less return) than right-clicking and saving to your Downloads folder.
Dante