I’m not sure exactly what the situation is here. To preview what the Eggbot will actually draw, select all, and then ungroup everything. Turn the fill type to “no paint” (none), and select a consistent stroke width, say 1 px. Then, you’ll see all the same lines that the Eggbot will.
If you want to draw the outline of a set of path objects, you might try using the “Union” operation under the Path menu to combine them together.
