Can new members not edit posts?

I am a moderator on another Vbulletin forum formatted similarly to this one, and we have a very distinct "edit" button by the quote buttons.

I can't seem to find an edit button on AZ...

 

its there, but goes away after a certain amount of time.
either 5 or 15 mins. I cant remember

 

The edit capability is set at 15 mins for good reason, and we have explored other options extensively. This is not going to be changed.

The primary reason for this is that too many people posted something they eventually regretted saying, and, after receiving many controversial replies, edited their post, thereby rendering the rest of the thread incomprehensible. In the Black Market, people were editing their posts after complaints were received, making a meaningful investigation of any claims very difficult.