Thanks GP! I like your "treat it as suggestion" idea. It can work out great
Oh & I neglected to mention that some sort of consistent, generic API would be required for bridging between the game and the hook. For example dictionaries and maps are trivial in python so the hook (python code) can expect some kind of Context structure passed to it that contains all the dictionaries, maps and lists that form the basis for the spell AI code thinking process. I imagine IW already has such infrastructure in place (in C code).
Last, I have programmed such hooks (from both ends) for big commercial apps and they were always one of the customer's favorite features. If planned correctly, with foresight of future needs, they make the product that much more flexible and long lived.