Possible Clues:

• Henry pretended to accept book that's incomplete
• Ill-conceived as a hopeless bloomer?
• Henry Faraday was left out in the sun? That's not been well thought out!
• A2: "I hope the plan isn't ___."
• Not well thought out
• Can't use your loaf if you're like this
• Like the idea behind this puzzle's theme?
• Not properly thought through - put back in oven
• Not well thought through - perhaps bread in oven
• Like the answers to this puzzle's 12 asterisked clues?