Ctrl++ to zoom in. Or click on empty canvas. (How’d you get the third pic?)
That’s determined by the size of the end mill. An 1/8" end mill can’t cut a 1/64" wide line. You’ll need to select the cut to be “outside” for the outer shapes, and “inside” for the cutouts to stay dimensionally accurate.
Try the X-ploder app.
Not the way you want. You can change the size of rectangles and circles easily, and you can input dimensions to locate objects as well. You design wouldn’t be difficult to recreate in Easel, but it gets frustrating when you’re used to using a drawing program with dimension tools.