Most of the webcomickers I know are so fiercely independent that I can't imagine them stealing someone else's jokes. And honestly the way that webcomics works, what would it profit you to steal a joke or a strip from someone. Even if you updated only once a week that would be what, one, two, three strips out of 52? Any more and the thievery would become quite obvious.
As far as the Creators Rights thing I'd have to say that at the time perhaps it seemed important. Maybe it even was. I remember before McFarlane broke off and successfully formed Image both comic companies were pretty cavalier about their stranglehold on the comic artist community. I think as much as he is sometimes reviled the comics community as a whole owe a huge debt to McFarlane for simply sticking it to Marvel and DC and removing that air of omnipotence they had. As they say, success is the best revenge right?
But nowadays that document is a bit of a joke. It represents a sort of unifying theory of behavior in comics that seeks to supersede the legal. I think what McCould says in the narrative above the document:
A few years later, several top-selling Marvel artists would break from the pack and form a new company called Image, shifting the debate from rights and principles to clout and competition, but both developments would share a common premise, still relevant today: that comics creators already have the right to control their art if they want it; all they have to do is not sign it away.
is really the most telling and most applicable statement to comics and webcomics today. The only ethics that are involved in dealing with a publisher or collective is what you agree to when you sign the contract. Anything more would require the unionization of the industry and I doubt (once again citing the independence and relative insanity of artists as a whole) that would ever come to pass.
Also the general rule of "don't steal shit" applies as well.
