This question specifically applies to Google Documents, not Google Spreadsheets (but if the answer applies to both, all the better).
Google Documents has built-in Keyboard shortcuts for Google Docs. I would like to define my own key binding or shortcut so that I can run a user-defined script on the document directly without using the mouse. For scripts that I want to run often, having a key binding or shortcut I can press saves me wasted motion from having to use the mouse to pull down a menu and run the script.
I have scoured the Google Apps Script APIs and found no mention of allowing this level of customization.
Do I conclude that Google did not include this feature?
I have not investigated possibilities of using Firefox-specific extensions but that would be my next approach (e.g., Greasemonkey).
Note that this is not the same question as asked in How can I create custom keyboard shortcuts in Google Docs?.