Personally, I think that the requirements for being a member are enough. It is important that once you are in you have full access to the benefits of the Forum, IMO.
It is inevitable in online discussion that someone is going to take something wrong or be hurt by something someone says. I believe we have to trust in the forum guidelines and the fact that the forum requires a professional and courteous discourse.
Besides, we create too many more rules or gates and we moderators will be sitting here alone!
My 2c...