I just came here to post the same: Without a search function + the ability to describe to forum posts, real discussions are just not possible. Please add both and make this forum a fun place to participate in!
Edit: For the time being I just search the forum using Google like this: site:oxygenbuilder.com/forums/topic/ <keyword>
but a forum should have a search function on its own. And without being able to subscribe to posts i'm interested in, I need to constantly check on posts I'm interested in - but of course almost nobody does that.