Rick, great job of rounding up those terrific memories. You hit the Peter Pan spot. Your recollections ring true of many of my childhood experiences.
"The City that knows how" knew a great deal when the Park and Rec Dept. staffed neighborhood school yards and playgrounds with recreation directors. Along with hours and days of fun we learned playground rules and how to negotiate social conduct. I've called it the politics of the playground as it helped inform us about human nature.
Sprinkled throughout this Message Board are other postings from readers about their recollections of childhood play. Editing those threads together into a chapter of childhood play in the Outsidelands would be a worthy trove.