Ummm, before I go on I just want to ask one thing: Whats the difference between these two options?
1. Only edit someone else's work if they do not object.
2. Edit only with the permission of the author.

By any choice, I've never really respected any person who edits other people's works. As in, most people in the fighting game world love to draw over previously made Capcom, and SNK sprites for extremely dull and uninspiring designs, or to the point where they look just plain wierd. Ditto this in with the Sonic edits, and Megaman edits as well. JUST STOPP, PEOPLE!! It's 'oogly. Now with editing anothers piece in a forum, I definitely do believe in. However, I don't think that everytime someone submits something, everyone should hop on it and edit everything to their liking, confusing the artist's original idea by making him decide who's style he must choose to suit the audience. In fact, that irks the hell out of me.
Call me stubborn, call me stupid, but I just believe that above all, an artist's sharpest sense should come from his/her ears, not their eyes. In other words, listening to response and understanding why and where someone is critiquing certain parts of a work is vital in understanding your audience, and how to better make your art speak to them. Of course, no real artist should ever forget that just like his/her fingerprint, their artistic style is one in a gazillion(what?...I counted elephants also...Elephants can paint too, ya know...) Despite this, I still believe that it is better to only edit a piece if the original artist who posted the work hasn't gotten it down yet, or if he requests an edit for a better understanding.(yes, yes, hypocrite is my middle name...)