To test x sync
take the back/groundglass off so you can look into the bellows (from the rear) through the lens.
Open the lens wide open (5.6?) and set the shutter to whatever speed you like but test them all when you get the chance.
Fire the shutter with camera and flash pointed at a blank wall and you should see uniform illumination through the lens with no sign of the shutter blades.
edit: I'd put the rayflash aside for now until you make sure everything is kosher.
that thing will probably rob some power so the quide # will no longer apply.