Possible Clues:

• Lack of courage
• Lack of bravery
• Bully lying beside a road with diamonds has a yellow streak
• Yellow quality
• It's craven for a fellow in custody to be so hard and cold
• Playwright barely took risks, showing timidity
• A beast a cried in a 2 down way
• It's yellow yet firm so to draw up what's frozen
• Not real coolness, entering battle: not bravery, either
• Option husband ignored, accepting protégé's timidity