I like what this offers, however I would prefer to be able to access each individual "report" via a direct command as opposed to a menu. It would make it much more composable.
If you look at the code they are all oneliners so you could just add aliases
Certainly, and this project could take on a structure which enables that sort of usage. A really great project with similar utility is https://github.com/tj/git-extras, which I think could provide a good model for refactoring git-quick-stats.