Can you shed some light on how to access those other three from the GUI (whether using the command key or some other means)?

Sorry forgot some steps...You also have to rebind C-y to 'yankAndSelect:' (https://developer.apple.com/library/mac/documentation/Cocoa/...)

For the most in depth info on the Cocoa Text System: http://www.hcs.harvard.edu/~jrus/site/cocoa-text.html