As you can see, I defined shortcut, restart system, but it is still not visible. Why?
Is it only shortcuts that have the 3 dots or ellipsis that are not working in Yosemite Preview or all shortcuts? I'm not able to get any custom app shortcuts to work in Preview using the Keyboard pref pane. However, as a workaround you can assign those same shortcuts to All Applications and they should work fine in Preview.
Same problem here... sortcuts work everywhere except for Preview. Also, the shortcut for the selection of content in the side bar ('contents only', 'Bookmarks','Contact Sheet') works even with the shift key pressed (which is not the shortcut displayed).
Assigning the shortcut to All Applications works also in Preview.