I must agree that not being able to cycle the action bars with hotkeys appears to be a boneheaded oversight.
This is something for which an excellent UI design pattern already exists, which has no conflicts with anything else in the game:
SHIFT + UP/DOWN - cycle through the action bars.
Instead of a keyboard action that takes a second at most and leaves the mouse cursor in position (if you are e.g. aiming at something which choosing action), we are reduced to a game of "hunt the tiny button" with the mouse cursor, clicking, and then having to move the mouse cursor into position, something that takes considerably more time.
