You know, I've been active for a few months and my impression is that most Freepers (other than the few obvious agitators that we all run into) are very comfortable debating opinions contrary with their own if presented in rational and respectful ways. After all, our underlying beliefs converge or we wouldn't bother being here, despite particular disagreements we may have on isolated issues. For me, the greatest attraction of conservatism has always been that rational thought is more powerful than dogmatic ideological belief.
Properly organized, such an event as suggested could be a modern Congress. A place where new ideas might bubble up. Potentially a whole lot of fun, besides. Who knows? Probably worth investigating though, eh?