Will taking valium the day before surgery reduce the effectiveness of the midazolam used for anesthesia? what about narcotics (affect on fentanyl etc?

No: The valium the day before will not have an affect provided you are not a daily user. Patients who require daily valium will have a bit of a resistance to midazolam, its not a huge deal the midazolam isn't the main part of your anesthesia. As far as narcotics these work together. it will not have a major effect and your anesthesiologist should be easily capable of caring for your needs.