Moved this from just a comment to a thread -

Are 'empty' holdings meant to be there, or is that a bug?

There appears to be no 'Commune' holdings I can find on the map. Is this intentional?

Is there documentation for how the Roman government is supposed to work, especially as a vassal?

Is there any point, as a Roman, to building any of the military buildings? You don't get any levies from them and that's half the point of those buildings.

Holy War CBs appear to be missing entirely?

Anyhow, that's just from like a half hour or so of messing around with Ave.