First question first: Mediums of sufficient training can sense those around themselves who have been touched by the gift, the untrained can only sense those who have been touched by the most powerful spirits. In other words "Miss Night" radiates a power that is more like a ghost than a living person and near her almost always is a powerful Ghost (Her Dead Mother)

Those not Mediums can sense either an unnatural chill or heat emanating from her presence that's unsettling[@XxLyraxX]

Yes I saw Hammy's Patronous, the Headmaster's CS is an old Teacher CS I wrote up for a different RP 
I'm using him here because I like him and I'm lazy[@Saarebas]