I have found all of these useful, at some time or another, and not just for plays. They make sense when applied to other kinds of writing too!
1: Things have been disordered. The drama continues until a disordered status comes to rest.
We don’t have to worry about creating a problem. We make a better play if we worry about restoring order.
2: It is the objective of the protagonist to keep us in our seats.
3: Alice said to the Cheshire Cat, ‘Which road should I take?’ and the Cheshire Cat said ‘Where do you want to go?’ and Alice said ‘I don’t care.’ And the Cheshire Cat said ‘Then it doesn’t matter which road you take.’
4: How do we keep the audience’s attention? Certainly not by giving them more information but on the contrary, by withholding information. By withholding all information, except that information, the absence of which, would make the story incomprehensible.
5: The deeper you can think, the better it is going to be. Deeper, in the sense of writing, means ‘What would it be like to me?’
6: Clichés in themselves are not necessarily bad. But maybe if we thought deeper, we could find a better way of expressing things.