I have noticed that you have a positive and contructive attitude to the problem we all have. I've tried lots of things, to try to help with this inconvenient, to put it mildly, problem with a little success. I find that it does help, if a partner, or someone with whom you are prepared to share your most personal problems, will co-operate. I think that most people feel some embarrassment and unease, when urinating of defaecating (I'm British!) within others' earshot, or even just leaving company for the purpose! Some of us find it impossible and we're the ones who are using this site. I've looked at the paruresis site you mentioned and, although urination isn't such a great worry for me - being female helps here, I think - it's still a little issue. The site is very good - informative and helpful.
I agree that there are some rambling posts on this site but, maybe, the 'ramblers' find it difficult to come to the point. Perhaps they also just need to offload their problems, which, I have to say, aren't always relevant but I expect that it's the relief of having an outlet that causes this outpouring.
The threads just aren't really threads. The posts are often totally unrelated to the original message.
All I can say to you, Chris, is keeping trying anything you hope will help. You're attitude is positive. It has to be, or nothing at all will help.