What are the pro’s and con’s of having a coach who is or was an actor as opposed to one who has never been an actor?

They've been in your shoes. So, you will learn everything they know and you will learn from their mistakes if they are generous with their trade secrets. You know the old saying, "A wise man learns from another man's mistakes." A word of caution: Steer clear of coaches who still wish they could act and are washed up. Some are angry and take out their frustration on their students. Choose the coaches who have experience and choose to teach because they love what they do.