Never wound a snake; kill it.
I love actors, both my parents were actors, and the work with actors is the most enjoyable part of making a film. It's important that they feel protected and are confident they won't be betrayed. When you create that atmosphere of trust, it's in the bag - the actors will do everything to satisfy you.
.. almost everything all external expectations, all pride, all fear of embarrassment or failure - these things just fall away in the face of death, leaving only what is truly important. Remembering that you are going to die is the best way I know to avoid the trap of thinking you have something to lose. You are already naked. There is no reason not to follow your heart.