As for Shu and Niall, that character is no longer on board but Nialls packs territory ranges from the Rockies over to the east coast and from just above the Canadian border to the gulf coast and parts of the keys. Because of the expanse of their territory Nialls father has a unique way of running the pack. While he is the Alpha he has several Beta pairs that have subterritories. He has many international contacts that included Shukura's father who is/was the leader of a large coven of vampires in England. However, like I mentioned earlier Shukura is no longer on board. 

As for other schools yes there are others but they are much smaller than Rosa Claire. There are a good several thousand students at Rosa Claire.