Python advice on Vassal States? [BTS]

[Headrock]

I'm trying to convert Greek World to BTS format, but also apply changes to the game as well, in particular wanting to use Vassal States instead of city flipping to emulate the historical events. My question is, are there any exposed functions in BTS that allow forcing a player to become a vassal state of another? And is there a way to force an AI to initiate a diplomatic demand for capitulation from a human player?