I was actually IN Central Park all afternoon today with my daughter. We went to the Beledere Castle overlooking the Great Lawn and all that...great stuff. I hate to say it, but it would seem to me that the City is basically right, in that there really isin't the room for model airplane flying...there are just too many people, too many other activities, too many other people(soccer and such) that want the fields...and no real way to control access so that model flying could be done safely. A one pound foamie beaning someone in the head would be bad...and there is no real place where someone could rope off an area so that people would not just lay down a picnic basket on your runway while you were aloft.
I don't see how or where a section could be cordoned off for model flying, and I don't think it's wise to fly without an area being cordoned off.
I remember about a decade ago meeting this Polish guy who was flying a pair of competition HLG gliders right in the middle of the Great Lawn in the summer. He was really good, he would toss them, they would circle around for about 45 seconds, and he would be running through great crowds of sunbathers and kids, stepping on people, chasing his gliders. It was funny, but really stupid, too.
When my daughter and I chase around a North Pacific glider or something, it's always like that, too. Too many people around.