There are at least 2 functions that are only available through the keyboard: Ctrl+Shift+LeftArrow and Ctrl+Shift+RightArrow for previous and next document. There may be others as well, but I know of these because I use them.
My issue is that this action is not available from any of the menus. It seems reasonable to me that all common actions (at a minimum) should be available via either mouse or keyboard. I might even be so bold as to suggest that this action is common enough to be worthy of its own buttons on the toolbar.