@thecorkboard, thanks for taking the time to leave feedback. Over the years, CommentPress has, in fact, been a standalone theme, a standalone plugin, a combination of standalone theme and standalone plugin - and is now a plugin with a choice of themes supplied with the plugin. As you can see, a lot of options have been tried and, crucially, it's just me maintaining CommentPress... the consequences of which I presume you can guess from that fact alone!
If you're using BuddyPress, I should mention that CommentPress is deeply integrated with it and that there are a number of options you could explore, depending on the nature of the content you're working with:
The simplest option is to install BuddyPress Groupblog and make those group blogs CommentPress-enabled. You can see a demo here, which happens to use the CommentPress Modern theme for the main BuddyPress-enabled site, but this is not required. That way, your existing BuddyPress theme would not conflict with CommentPress and your group members can write and discuss their work in the group's blog. Activity items are, of course, created by activity in the group blog.
If your content is static, like for example this development site which is set up to discuss Thoreau's Walden, then there is a newly-written plugin (which I will release on the WP repo soon) which enables a number of BuddyPress groups to read and comment on the text - both singly and together. In this instance, Walden itself is a CommentPress-enabled site, while the main site is powered by Commons in a Box.
Both of these approaches require WordPress Multisite, which may not be to your liking or which you may consider too technical, but I hope this gives you an idea of how CommentPress can work with an existing setup.