=/ Just because it's previously there, that shouldn't keep you from editing it. I'm pretty sure that's what signature making is all about actually...
You're going too far making that statement. Learn about them a bit more than actually saying what they are about.
^ Incorrect. It's about editing whatever is necessary to accomplish a good end result. You should definitely cut out the rock and move it up so you can see it going into the water and then make it blend into the water. Would do a lot to make it looks less 'renderish'.