General developer forum

Hi. I was wondering about the structure behind the moodle.org website itself. Namely, I am designing my own moodle based site, and I want to have both forums and classrooms. I noticed that when you view all forums on moodle.org, you are really looking at a collection of courses. Although 99% of the forums are located in just course id=5. If you had both "forum" courses and "classroom" courses, but wanted a separate course/index.php is that possible as-is?

Also, I noticed that the docs are in their own subdomain. Is that to distribute the load across multiple servers, and if so, I assume it uses the network scheme (http://docs.moodle.org/en/Moodle_Network)?

I am wondering if I should not build my site out of 3 different moodle sites instead of 1. My thinking is site A would be classroom courses. Site B would be forums and other supporting rooms made out of courses. Site C would be courses used for mini website for non-profit organizations. If I did this, it appears to me when I read about Moodle Network that a user who signs up for the main site A would be auto logged in when visiting B and C. They could enroll in anything that had rights to, etc. Seems to me it might help if I have to do substantial modifications to the look and feel of the course intereface, as I want the rooms on site C to not feel like classrooms, not allow charging, be open to all guests by default, etc. While the site B forum and support rooms are open to all users, and the Site A classrooms woudl require fees or keys to get in, etc.

I assume there must be complexity and maintenance issues once I do this 3 site scheme. Are there are BIG reason I should keep it all in one?

Any thoughts on this are appreciated,
Jamie