I'm noticing a lot of links to other threads in this forum and to articles on Richsoil that don't look like they were put there by the authors, several threads even link to themselves in the first post. Do you have this forum doing that automatically?

Yes.  It has done that for about a year or more.

I recently modified the algorithm so that for any particular thread it does it no more than once per thread (I noticed some threads had 50 links all to the same thing) - and while I was in there tinkering, I added some more links.

This is something much like what wikipedia does and some other sites.  I think it is a big part of what html was designed to do.