To answer your first question.... Yes. Less people will go directly to a separate section and anything posted in there will be less viewed. A sub forum is not a thread within a thread, it's a separate sub forum within Comp (same as Mentoring, For the Board sections we have)
And here's another challenge we always encounter with idea of more sub-forums... The more an exception is made for one type of sub-forum (ex Roll Calls or contest annoucements), the more it opens the door for requests for others whether within Comp forum (ex. Comp Results) or Q-Talk breakouts. Then all the info gets scattered all over, also makes more work for the mods to move stuff into the right forums (believe it or not, members often put new threads they create in wrong places and we constantly clean it up). Check out all the other BBQ forums with so many sub forums for every possible category breakout, and you'll see and often hear that it becomes messy and why would we want to be the same as others ?)
comp activity forum activity only really gets jumping for 3 or so months then dies down considerably.. Why have a separate sub forum for areas that are going to be relatively dead for 9 months a year ? As well, some of the most viewed & posted to threads are Roll Calls, Announcements, Results - why move some of the most popular stuff ?
We added the highlighted/ colored forum pre-fixes for a reason - To make it easier for people to see those that are interested, and also easier for those who have no interest to skip over them.