My forum users and I find the UI very confusing too: it’s cluttered and has a lot of duplicity, as I pointed out here.
What I did:
I installed the closed side bar by default theme component, since the top menu fulfills does much of the same for the normal user (you can chose the category, the tags, send chat messages etc.):
I set the initial page to “recent”, instead of “categories”, so, as the user opens the forum, they can already see what’s being discussed etc. (the categories page was too hierarchical for my people, who don’t necessarily know what they’re looking for when they access our site)
Thank you everyone for your valuable advises. I havent had the chance yet to look through all of them.
In the meantime, please allow me to ask a follow up question about best practices in terms of Channel/Category Structure. Is there a guidance for a simple and helpful ““Table of Content”” from you?