Twice, in this topic, you have written "basically, I am running ... ". I commented on this, the first time, and I wrote in reply that it makes it very difficult for us to provide detailed assistance when we only have this very basic information. Perhaps I should have written plainer: can we see your Kunena configuration report, please?
If we see your Kunena configuration report we can then see all the settings you have used, including the settings that control how you have setup new user moderation.
The advice you have been given is to upgrade to a newer version of something and you do not "want" to do that, for some personal reason, even though this is probably very good advice and will fix the problems you are currently having. That's entirely your choice, of course, and I have no other comment in relation to that. As I have written before, I do not know how to address the problems you are having with JomSocial or the FB Connect login feature.
You have asked if it's possible to disable "new topic moderation". I am not familiar with the term "new topic moderation" (just as I did not understand what you meant when you wrote "disable the topic moderation altogether"). I will take a wild guess and say yes, it's possible to disable "new topic moderation" but, until I have seen a lot more than just "basically I'm running K 2.0.4, Jomsocial 2.6.2 and Joomla 2.5.8", I can't say for sure.
Did you take my advice and upgrade to J! 2.5.9 as I recommended earlier? Or is this, too, something you do not want to do even if it may fix the problem? :dry: