I have a mod that I developed that allows you to specify whether an option is "Required", "Verified" or "None" by using a drop-down box next to each option.
If an option is "Required" then the customer cannot add to cart if the field is blank, "Verified" asks the user to confirm the blank entry before adding to the cart, finally "None" is not validated at all.
Email me if you are interested....
Al Ponte
agponte@infosolvllc.com