Need help - Weight distribution hitch installation pics

You are getting close, and suggest lowering the hitch head one more hole. As from the picture...it is pointing up a bit. Tongue pointing should be level at it's highest pointing and prefer pointing slightly down

As for washers, they tilt the head backwards, towards the trailer, and that makes the trunnion bars point lower. That in turn provides more 'potential' tension you can impart on the trunnions...meaning more weight can be transferred to the TV's front axle...which at this time don't think you need to do