I have had a lot of experience building wordpress sites like this one. Would anyone be opposed to me adding a tag cloud as an additional page. This would allow us to create an easy way for us to review the course content based on tags, since both comments and posts can be tagged. The user can choose where he/she thinks its better to post. However, everyone and the instructors are able to see it in one location. This could also help us build the venture lexicon when posting information that could be useful as resources later on. This also solves the confusion around where to post.
I could easily add the tags as they are in the categories. And people could feel free to add there topics as well ie: social media, 3d printing etc…
Let me know your thoughts,