I agree that in this forum it doesn't make much sense to edit someone elses work unasked. In the critique forum, where people are posting their work asking for other's opinions or suggestions, I think that a picture can be worth a thousand words and an edit that illustrates a suggested change is often a more effective way of providing feedback than a confusing written explanation.
I hope that everyone feels free to offer me any suggestions on any of my work in any way they feel best puts the point across - especially in the critique forum but for my work, anywhere they see it. That feedback is what I see as the strongest benefit of this community since I don't have a good source of honest feedback from people whose work I like other than here. It's much better than the "Oh, this is nice, I love it" comments that I get from family and friends or happens in some other online venues.
When someone takes the time to download my pic, work on it, and repost it as an illustration of suggested changes, I think it is a real gift they have given me. I don't always agree that the suggestion is an improvement, but it is nice to see how someone else sees things.
Thanks to all of those who do offer all sorts of feedback, please continue to do so.