I would know everything about the company; how long they have been around for, what courses they run, the type of student they attract, who the boss is etc etc
On the flying front, questions such as "Have you ever frightened yourself flying?", "Have you ever made an error of judgement whilst flying?", "Have you ever misread the weather forecast?" are questions I have been asked.
You may not get asked about instructing but possibly questions about your flying to date.
Good luck.........TJ