Without a doubt chainBB is one of the coolest forums I've seen. I feel like the way it categorizes things is so much better than steemit.
Some suggestions after going through it for a while:
As a new user, not having a Post Now button on the home page made it a little overwhelming trying to figure out how to make a post. I think if you added a button to the home page it could possibly take the user to a screen that allowed them to pick from categories or a dropdown listing the popular ones.
Before I clicked on any of the categories on the home screen I tried to do a search based on what I was looking for, "Poetry" for example. When I typed in "Poetry" into the search box it listed a few posts, but did not result in the category I was looking for. My suggestion is to have 2 search fields; one for Post Search and the other for Category Search.
In order to prevent users from creating their own categories and subcategories (as this could just create a mess on the forum) I think there should be a section to suggest or request that new categories be created. Maybe allow them to define the primary tag that they want, but if it isn't already an existing category/subcategory within chainBB then it would would have to be approved by admin. Until that happens its categorized under their next tag that is used for their post.
Post Body box size adjustable (just vertically would be fine).Overall, #chainbb is awesome. I hope there is some way that we can find ways for this to be used for other crypto projects soon. Looking forward to the next version!