nice thread, doc.
but i guess it's fighting against windmillls. i have the same (naive) requirement for "discussion boards" but this approach is a pain in the ass when "forum culture" starts its absolutely typical communication-scheme. if a community is just big enough, on each task you'll receive the all-in-one solution from extreme intelligence down to extreme stupidity. you can't control it, even if you have mods, even if you have only good purposes when you open a new discussion.
but in fact, we can't blame anyone for being "a human with own thoughts and ways to live". we just can hope, that those people we share sympathy with (which doesn't mean that they have to agree on everything) won't run away because of those people who disturb the (subjective) peace.