We love St. Pete Beach! My wife's grandparents and parents have been visiting since the 40's. SPB is totally laid back.
Tee shirts, shorts and flip flops is the dress code there. I always say SPB is more like Key West then Palm Beach. Relax and leave your formal wear at home. Our kids are always safe. We never have an issue with them walking on the beach day or night. Not to worry Mom and Dad, no college parties or crazyness here. This is a great family place, very peaceful and quiet for you snow birds escaping from the harsh northern winters.