I think that's part of the problem, every time you add an action/event, Construct deactivates the highlight focus in the event sheet, and there is no way to use the arrow keys *OR* tab to get the focus back, instead you have to mouse-click inside the event sheet, and only then can you make use of a keyboard shortcut, but that breaks the flow of being able to use keyboard navigation.
After adding an event/action, the yellow highlight focus should not disappear, which would allow users to leverage the keyboard shortcuts to save time.
Right now, in order to make use of the keyboard you have to:
Mouse-click to highlight an event
Type A to add an Action
As opposed to:
Mouse-click on the hyperlink 'Add Action'/'Add Event'
Does that make sense?