Load the .GPX (or was it .KML ?) into Googleearth.
Then zoom to the layer and pan/zoom to the area of interest, stepping forwards/back to watch the progress of the aircraft/missiles.
Bear in mind that 'extreme' wiggliness seen from the launcher (or close by) is actually barely weaving when viewed from side/above ~ you should at least 'glance' at the end view before deciding how good the guidance has been.
There was a GE bug with how the elevation and speed graph was displayed (maximum greater than axes scale values), but SAMSIM is "correct", and the error lies in the external program.
