As for the story thread itself, the whole story would be contained in the first post. For those with chapters, people would be able to toggle between chapters in the first post. (Authors would be able to add a new chapter via another button separate to post reply and do it the same way as currently done - reply box, etc. Because screw ways like ffnet which require document uploads for each chapter).
This sounds fantastic. If it could be implemented, it really would be amazing.
Maybe a mixture? Old archive and an option for people to convert threads into this new form as well... unless in general people don't mind doing it themselves and just reposting fics from the beginning.
I'd like to see an option to convert old threads, as opposed to reposting. Many of the files (and their backups) of the stories that I've written and posted here are not only over 500 pages long, but are hideously corrupted in places that means that the only surviving copies of them exist in the ether of the Internet. It would take a long, long time for me to recover them and repost them, and I'm not entirely sure it would be worth the effort.
Of course, that's just me, and I'm aware that other people may be better able to just repost right away. In that case, I'd... well, I'd probably have to leave mine as an archive, so I think if there ends up being no option for conversion, then I would like to see the old forum remain as an archive. We could set up a static catalogue for that archive and then leave it alone; that would make sure it was at least moderately usable for anyone interested in the old completed stories.
As for ongoing stories... I suppose if there's no option for conversion, then we will all simply have to repost. Which is fine by me, since I'm not too far into my current one, but I can't speak for everyone.