Sorry to hear about the issues. Regarding the undo, the crank should be rotated counterclockwise, almost a full circle. But you need to collect an undo crystal first and to have fallen from somewhere, making a little number appear. The first room doesn't have an undo crystal, as it's more of an introductory level. You can finish the room easily in case you didn't already, then in the second room you'll be introduced to the undo. Maybe you've done that already, if not please give it a try.
As for the keys not working anymore after trying the crank, I managed to reproduce this on the Simulator. I know it's a disappointing answer, but unfortunately I have no control over how the Simulator behaves. What happens is that once you click anywhere on the Docked checkbox, the angle textbox or its up/down buttons or the slider, it takes the focus away from the game and puts it on the clicked widget.
SOLUTION: The good news is that you can avoid running into the controls issue. You do not need to click the Docked checkbox or the other widgets to rotate the crank. You only need to click inside the crank circle (the one on the right) and drag the indicator around counterclockwise. This does not cause the game to lose focus.
Hope this helps. Let me know if you run into more issues. And thank you for trying out the game!