Tom,
Your "outlines" are a result of the method you used to trace. As it is, both sides of all lines were traced (except the two rectangles on the bottom left - you probably drew these two vice tracing them). If you zoom in on your roundels, for example, you'll see eight jagged concentric "circles" vice four. Your circles may appear smooth, but each jag requires the cutter to zig zag, so the cutter will seem to shudder as it negotiates all those turns. Youtube has explanations as to why the double lines happen - search "Silhouette Double Line Trace" - for example go to 9:47 in this old video.
Also, your made your entire layout a compound path. You may have wanted to group them?
To "fix": use the Select tool and right click on any part of your layout, and then press "Release Compound Path". That will allow you to select each individual line, so zoom in and select a path (outline) you don't want, and then hit Delete. Since you have many markings in your layout, this method will take some time. Important-- when done, be sure to group each individual marking, or group all, or Create Compound path.
The Silhouette Studio trace feature is improving (slowly .. works "OK") but does not have a Centerline Trace. So if you can't download the required vector font or graphic, you could manually trace using the built in drawing tools. For example, all it takes for the roundels is drawing four circles and then aligning them. Alternately, you could use a program like Inkscape to do a Centerline Trace, save as as vector (like SVG or PNG) and import into Studio to have ready made cut lines. BUT ... much easier to manually trace in Studio!!!
Gene K