There is no current intention to introduce more sections into the Forum and after reading the recent 'Building a Layout with my ........' threads, I feel that they fit perfectly into the 'General Discussion' area, or of course DCC or Railmaster etc if that happens to be most appropriate. I am not personally convinced that the title needs to reflect the building partnership but there is certainly no harm in mentioning it in the initial post. As moderators, quite often we try to discourage (or even change) titles that do not actually reflect correctly the nature of the question because this also ensures that future searches show more meaningful threads.
The benefit of keeping them in the Main Sections is that the Forum members with particular knowledge in a given subject will see those posts and be able to help, especially if the title is appropriate.
There are already threads such as 'Let's see your layouts' that contain pictures of members layouts. Pictures can be posted in any of the Forum sections or indeed any other thread that you may raise. They are moderated by Forum Admin, usually during office hours, so pictures posted at weekends will usually be cleared early the following week.