To the best of my knowledge, the short answers to your questions are:
dsibilant wrote: Any idea of the RAM usage the system needs, especially versus systems like Phorum, VBulletin, phpBB?
These are all different products and it would be unfair to compare the memory usage between standalone forum software—phpBB
which requires Joomla in order for it to operate. Although these standalone products can be bridged to use with Joomla, they operate quite differently. If you want to know more about Kunena's memory requirements, I suggest you read the
article in the Wiki.
dsibilant wrote: Can the threaded view be made the only view users can employ?
It depends on what you mean by "the only
allows users to choose between several views of the forum and that, perhaps, is one of its attractive features. Remembering that we're all different and have different preferences, it may be better to allow your users the flexibility in their choice of how they interact with your forum. The short answer is that it's possible but your users may not appreciate the choice you make.
dsibilant wrote: I want to integrate my site's normal content with the forum. Is it possible to enable guest comments on an article, and have those comments put onto the forum in a new topic or as part of an existing one?
Yes. This is achieved with the
Kunena Discuss plugin