Is there any point in this interface?
I know it uses MW syntax, my point is that it completely changes the method of editing discussion threads.
The current method is used on every wiki that exists at the moment, and the number of pages where it causes a problem is negligible.
TBH, this entire system is silly. If you want a forum, you know where to get it. Trying a hack to turn MediaWiki into forum software is trying to make it do something it was never intended to do.
It was never intended to do what we do with the Saloon bar either.
Personally, I think that would be the best idea. You've made this look much better than it originally did, and I can see it being useful once some of the oddities have been ironed out, but there's only so much you can do with it and forums ain't it.
Might be worth a look.