I never edit other people's posts. If they double posted I would delete the extra post, since that happens at times. I feel when moderators and admins are purposely editing your posts it looks bad and I wouldn't want to be on a forum like that.
I edit posts only on two conditions, one, it has promotional link or suspicious link, and two the title has a typo. I do not edit the content. If the content is poorly written, too poor to be understood, I delete the post. Sometimes the post or the topic is good but it has a type on the title or it has a link that you do not approve, in situation like this I feel that editing post does not hurt the community, and is not even against freedom of speech