First off, how are park flyers supposed to exist if they can only fly at "dedicated" flying sites? Very few parks have dedicated flying sites.
Think it's about time you sit down and take a look at the [link=http://www.modelaircraft.org/UserFiles/PPP-SiteBooklet.pdf]PPP program package[/link], so you can be on the same page as the people that support the program. It's chock full of questions and answers, forms, marketing materials and videos so you, the modeler, can take approach your local parks dept director and perhaps get your own field and club at your local park. Check it out, it's free to download. And if you ask nice, they'll mail you the complete package. But don't forget to take a [link=http://www.modelaircraft.org/UserFiles/PPP-SiteManual.pdf]look at the manual too.[/link]
Secondly who is supposed to decide/take responsibility what is an appropriate flying site size or what the separation should be for such activities? You? Me? The other guy?
C - The other guy. Again, revert to the PPP program guide. It's loaded with information you pass along or present to your local parks director to see if its in the best interest of their park and their park owners (taxpayers) to start their own PPP flying site, whom just so happen to be the people that decide on behalf of their members (taxpayers). If you would have said D - God, I would have went for him, he makes all decisions for us anyhow, but he wasn't listed, so I jumped back to the mortal decision maker instead.
It's really not that complicated LCS. It's been going on for years .... but now it's easier, targeted ... and now cheaper! Oh and most importantly, supported by the EC and 300 AMA members for all your Q&A's.