The old forum platform was really outdated and started giving us troubles a while ago, so the change was pretty much inevitable.
With that said the first priority was to keep the old data and structure then get the new forum up and running.
As for opening the forum a bit, it can be viewed by guests, but only registered users can post, download attached files and view the pictures in their full resolution (the thumbnails are rather small).
It is possible to add hidden sections only for registered users down the line, but right now it is undecided.
Probably it will be tied to a structure overhaul.