Shortcut: Page-width with toggling between it and previous zoom level.
Many suggestions!, but I've found, especially, [Zoom: Page Width] to be especially useful. Sometimes I can toggle the Inspector and palette sections to disappear for full width of the score on the screen, and sometimes afterwards I will zoom in later. Upon re-enabling [the inspector] and [palette], I'm still in zoom mode of where i was. [Zoom: Page View] is especially nice to get the page to fit into the entire area again. It would be nice to be able to do this quickly with the keyboard rather than have to click it from the drop down area where the percentage of zoom levels is located.
And if that were added, maybe the others like "Whole Page" and "Two pages" could be given shortcuts too, or even another option would be to have a "cycle" through which is similar to what is available with Page/Single page/Continuous (there's a cycle shortcut for those already as "Toggle View Mode")