Every time i use the Inkscape trace feature, I always get lines that are actually two lines/curves with black filled in between. Makes it so hard to edit. it looks like your traces are the same. Does that give problems with the vinyl cutter? Does it cut both lines with spaghetti inbetween? Is there any way to force it to a single line/curve at the transition from one color to the next?

I just did the stencil art for a Gameplan Sharpshooter. It was fairly simple and I just hand traced it in CorelDraw over the photos and sent it off to be cut and backed by Gamestencils.com. Worked great. Autotracing attempts on it were terrible because there was so much overspray and speckling on the original artwork.

Did you mean to paint your fence?