Thanks for the detailed answer. I'm not sure if we have a valid need for more than one neutral option in a group separated from the bias options, but I can definitely see how this would be useful in other survey scenarios. I will keep it in mind.
I really like the "% of those who gave an opinion" alternative - that may be the best compromise option we have thus far. It allows us to preserve data compatibility with the previous surveys, while still allowing us to present the executive with a view of the data which suits his needs/desires.