Thanks for the comments. I have given this a lot of thought as I looked over how other platforms deal with this issue. I believe that people both make mistakes when they post, and they change and grow. So having a permanent unchangeable record is great for a news source, but not so good for a friends community. When people can reword, rethink, revise, fix typos, or delete bad ideas, they are more willing to engage. Some sites may want to be a clear record, but others may want to be more like a friendly conversation where people have the "right to forget". Texting has the immediacy of spoken conversation, with the permanence of the written word. Thus, often texting has knee-jerk reactions that never ever just go away like they would in a spoken conversation.
To deal with the issue that Johnk brought up, with comments perhaps not matching an edited original post, I suggest having Cheetah send a note of a change to anyone that commented. Then they would have the opportunity to adjust their comment or delete it.
Also, perhaps a site specifically doesn't want to be a permanent record. Could we have a setting to delete everything posted after a certain amount of time? Perhaps someone could mark if they want it to stay, or how long it will stay?
Most social network conversations are pointless after a week or so. Telling a friend Happy Birthday doesn't need to be stored for permanent record. Their are many reasons for a site to choose to let the back and forth just vanish. Let's face it, I didn't need Facebook reminding me that I used their platform to let my family and friends know that my father died. I didn't use that platform when my mother died, because I didn't want that popping up in some "memory". I got the information out, I know when and what, now let me forget it.