010101 I'm not sure I understand exactly what you're trying to achieve. To answer the discussion title, an extension should be able to remove the title requirement relatively easily by tapping into the DiscussionValidator. The more complicated aspect is probably what you want to do with the discussion list, because it probably won't be super user friendly without any title.
As for having the title be displayed as part of the content, it should also be relatively easily using the javascript extension API to concatenate the title and content. But there could be issues depending on your goals since title is a non-formatted text and content is a formatted text. And if you hide the original title after concatenating the title and content, there's the same question about what you want to render in the discussion list and search results.