Re: Do these bunks extend too far?
If your trailer is sized appropriately, there is no reason for the boat to be hanging off the back ... that is to say, the transom of the boat should be over the rear of the trailer frame, give or take a few inches either way. The bunks should then be sized and positioned accordingly, to provide maximum support for the hull, and especially the transom, where the weight of the motor bouncing down the road exerts enough force to damage the boat, as it has done here. The transom saver should prevent this if it is attached and positioned properly. The photos do not clearly depict how the transom saver is attached to the trailer. Perhaps that is the problem, or perhaps the transom saver was added to the rig after the damage had been done.
If your trailer is indeed undersized, you may improve upon the support it provides, but it will never be as good as a trailer that is adequately sized and configured with a properly positioned transom saver.