@ shattered sanity....people are given access to the poobah forum after any of the following:
1) they have posted 3000 posts or have been a member for 5 years
2) have given a donation to one of the community fund raisers
3) have volunteered their time as a liaison, moderator, administrator
There may be more things I have missed but these are the main reasons access is given to this forum.

Like IchbinkeinTeufel explained, posting is safe from google search so no one other than those given access to the forum can see the posts in that forum. I was thrilled about that as it was a place that my ex couldn't possibly see what I posted just in case.

You can post anything you would normally post on any of the other forums. Same general rules apply.

Hope this helps with better understanding