Another option could be to at regular intervals to do a spread (again, various options) this could drive narrative by showing certain characters in opposition etc. Or that could be a massive distraction just interperiting the cards.

My preference for setting would be rival Houses within a city. I think school could easily loose the premise in the usual school-drama and Kingdoms, well I certainly know RPs of that scale are popular but I can't see how that scale do anything but minimize character interaction. A city is easy to justify daily interactions between characters but allow the factions to also have their own domains.