This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Yes, you can have script in body of the Classic tag. The script is process if the body-content is set to JSP. If is tagdependent it is treated as simple text. for body-content is empty/scriptless it is translation error.
Answer to your second question, it will throw exceptiom.