Those are some great ideas. I feel like you could achieve something close to what you're describing (albeit requiring some manual effort) by A) designing a fo

Those are some great ideas. I feel like you could achieve something close to what you're describing (albeit requiring some manual effort) by A) designing a forum solely around subscriptions (akin to something like twitter followers with a threaded view) B) giving OP moderation rights within her thread to split posts into a separate topic at will, in order to maintain "on topic" discussions C) auto thread pruning of split topics and one or two other things.