AI Building Preference

I want to help the AI build necessary buildings (farm upgrades, towers, etc.) before building unnecessary/overly expensive ones (Royal Courts, 80% farm upgrades on Cyprus, etc.).

I know of the Build_Prod file, and the column where each building is assigned some sort of numerical preference per type of faction (CATHOLIC_EXPANSIONIST_CRUSADER, etc.). I assume the larger the number, the stronger the preference to build each building, but that may be wrong.

What do I need to know when editing these values? Are there other values that affect which buildings the AI builds?

Is there just a simple build order that tells the AI which buildings should be build in each province in which order, per culture, economic situation, and era? That seems ideal to me, because it would allow for the fact that certain farm upgrades are good ideas in some provinces but not in others, and certain provinces give valor bonuses, but no sense in building the required buildings for a unit in Early that you can't bulid until High (Toulouse bankrupting France by trying to go straight for Chiv Knights, in Early, for example).