Floating Namespaces
In 3.x, we can completely remove the namespace "hierarchy" as it now exists. Despite all our attempts to reword things, the "Top-Level forum" concept seems to be extremely confusing for users who are new to VaultWiki. Instead, it should be possible to assign any forum to any namespace. Rather than choosing a "Top-Level forum" in the Namespace Manager, you would choose a "default forum", and assign forums to the namespace individually via the Forum Manager.
This would result in chaos when constructing wiki forum bits, because the parent-child relationship would be gone, and Display Forum inheritance would be impossible. However, with the new namespace construction format, Display Forum would be obsolete. Namespace bits would require their own forum bit constructor, and could be processed based on a Wiki Parent setting as well as the standard Parent Forum.
These changes would actually make namespaces even more complicated, but eliminating Display Forums and putting the hierarchy stuff in the Forum Manager would make it feel more streamlined to new users, and allow for greater flexibility among advanced users.