Instead of asking about promotion, you should ask what it takes to be a rockstar employee (what past employees have done or what they wish an employee would do). That usually gives a pretty clear outline of what it takes to get to a promotion. It's also helpful to ask why the position is open, and, if it's because an employee is leaving, why they are leaving.
I never ask about salary in the first interview, but for the type of position I have, it is usually never just one, so there's plenty of other opportunities! (I think I did four for my current job.) I wish more employers were like you, Library Dragon, and just put it out there.