I'm afraid I don't understand the rational for the revindex. More specifically, why civics can alter rebelliousness levels but buildings cannot. I would imagine that a wonder like the Taj Mahal would inspire ones people to unite, whereas a slave market would inspire revolts.

So my point is, why is there no rev modifiers for buildings? And also, if I want to add them myself, where are the civic ones in the sdk? (and are they commented well?)

Look at my code suggestion post on adding the functionality to Traits, should give you a good idea of how to go about it. Basically it loads the values into the SDK, and then exposes them to python, but all the functions and how they are used are done in Python.

Buildings are mainly handled by their existing effects in game: happiness, health, defense, etc. The construction of any wonder has a short-term positive effect empire wide, but no permanent effects currently.