Not to harsh your high or anything, and I appreciate that you're thinking about different ways to spread the message, so I'm not trying to dis you here.
But a forum is a means to an end, not the end itself. It is a means to spread information, facilitate communication, help to organize action.
An infinite level of subtopics... What would that mean?
There are already an incredible number of ideas floating around. But very few of them actually come into fruition. To actually realize an idea takes a lot of energy and manpower. But such a giant forum, to me, sounds like a labyrinth - something you might fall into and never get out of.
I don't think that there is a direct relationship - that more forums lead to more action. I'd be tempted to say that the opposite is true.
What I know is that there is only so much that one person can do. We are limited by physical constraints - time and energy. Ideas? I have a million. What I don't have is the time / energy / money to implement them.
So what is the end you're trying to achieve?
Who is Cornmeal Smithy?