I think for experienced DM's there aren't very many questions. Ideas have to be worked out and most good DM's work out the answers to their own questions. The lack of idea sharing comes partially from the fact there there would be so much information to offer. I have piles of old ideas that never had a chance to be played, and I simply keep them in a folder and a small notebook.
I think "Plots and Places" would make a good heading for a regular article hosted here rather than a messageboard. And in fact I'm all for having regular articles here rather than letting good ideas fade into the depths of the server's search function.
But that's for the meta thread.