You just discovered the gap between marketing and the real world. There is no "easy Button" for converting scanned images to vectors. Either you cut it all ragged, or spend the time to clean up the scanned image and more time to clean up the auto trace. Line drawings of simple artwork with distinct color or B&W edges work pretty good (and that is what is used for demo and sales illustration) but low resolution images (less than 300 DPI native resolution) or aliased photos are a joke. Seldom in the real world are you presented with a high resolution line drawing type image to work from.
The solution is not more software or different settings. It's to build your artwork in a program (drawing program) that has good vector drawing tools and will import the bitmap file. You lay a "layer" over the bitmap and hand trace to get what you want. It's slow going at first but as you learn the tools and tricks the tracing goes faster and faster and you get to know where to make objects and what will cut and what won't.
I do a training course that teaches how to get from an idea to a plasma or router table quickly. I use CorelDraw for artwork and hand tracing. From there a nice clean DXF goes to SheetCAM for toolpathing and then to MACH or EMC.
Since we do decorative cutting commercially if there were a magic solution I would buy it (and I have tried a LOT of programs) but the truth is they all have problems with anything not simple images.....when you need auto trace the most!