Definitely Olivia, he would be nice to any previous or current students too. Given they have been around for a while, I can see them knowing each other...likely not good friends, but he will be polite.
Dem will get on with Izzy mainly cause of Ridley, I bet. He'll think Emil is a weirdo but not be a total douche. And yes, Su. Friendliness from Dem because of work connections.
Ronan wants to be both of their friends. Olivia can come to his work place and get free drinks. /winknudge
Jared is just going to buy their affection with confections.