First, the Religion Forum doesn’t “limit participation by critics” on open threads such as this. Your very posts’ continued existence proves this. The only exception is on “Caucus” threads, which this is not.
Second, for better or worse, the technical functionality of the Forum defaults to all subfora when first loaded from the homepage. Thus, all the fora, and the threads therein currently discussed, are visible on the main page of FR.
It’s not mandatory to view all threads though, and so if, for example, you don’t want to see the Religion Forum threads you can simply click on “News/Activism” in the “Browse by Forum” sidebar to the right on the main page. This will then open only “News/Activism” posts and threads, no religion, no chat, etc.
Here’s a direct link:
http://www.freerepublic.com/tag/news-forum/index
And, for the record, I enjoy reading most of the Religion threads even though I don't always comment on them. Some of them I've even printed out to take to my own women's Bible study group for discussion.