I'm all for making things better, but I should emphasize that I'm enjoying the pace so far. My assumptions is the back and forth threshold has more to do with the community than the layout.
Do I crave more back-and-forth? Not really. Frankly, if the conversation gets much longer, I think it warrants a fresh post for more attention and more space for insight. It would be over handling the features to create an efficient way to link that post to the initial back and forth (option to creat a new post from a comment maybe), but it's a gratuitous inclusion for someone to do manually that I wouldn't mind zapping when I saw it.
doom thread cost increase. if you want to keep it going, it will cost! or, after a certain amount of comments a little popup “consider making a new post here”. just throwing things out there, I like a good battle of wits that goes on and on. it’s what makes the internet fun.