I am so sorry: that was a Typo.
It is just plain "Option S" which opens the Sync Panel: all currently-selected files will then take their cue from the First-selected image. Only the settings which you check will be applied.
Also a very nice feature in ACR, is that if you multi-select several images in Film-strip view, and then move one of the editing sliders, you can change that slider-setting in all of the currently selected images simultaneously.
You also have multiple Undo and Re-do (with Cmd Z, Cmd Option Z and Cmd Shift Z).
Regarding keyboard shortcuts to move through the tabs that exist in some of the panels - e.g. 'Profile' 'Color' and 'Manual' in the 'Lens Corrections' panel: The TAB key cycles from line to line in most panels but I don't know of a way to flip between tabbed items in a panel such as Lens Corrections.
Within a Tabbed Panel, Tab takes you to the first item in a section then if you enter a new value there, it advances to the next line. If you don't change the first item, Tab takes you to the next section.
Also check on the microscopic flippy arrows in the top corners of the Film-strip column and also in the main Sliders column for Drop-down menus to useful shortcuts and links to other functions.