What are the 4 shoulder washers used for?

The four included shoulder washers are meant to accommodate smaller screws in case the original holes on the ball plate are too large. These washers will reduce the risk of smaller screw heads stripping through the larger holes, and can be used with any of the holes on the ball plate.

Is this mount designed to attach to the back or the bottom of a Raymarine Axiom+ 9 MFD? And would you have photos of this?

The RAM-D-111B-IN1U is intended to attach to the gimbal bracket from Raymarine.  There aren't any images of the Axoim 9+ MFD on that mount on rammount.com, but there may be some posted from customers in fishing or Raymarine forums.

Do you sell this mount without the ball adapter (or is the ball removable)? I would like to attach is with a hex bolt, such as a 3/8"-16. Thanks

The ball is not removable on this componet; the post of the ball is one solid piece with the plate casting.