Shortcut for opening applications stack on dock bar
ctrl+fn+F3

..selects an item of the dock. You can navigate using the arrow keys. The selected item is the one that will be selected first the next time you use this shortcut.

Once you've selected the Applications folder, the shortcut becomes for the next time:

ctrl+fn+F3+&#x21A9;



BTW:
You can also use ctrl+fn+F2 to access menubar items.