You probably have the trailer too deep. When I am pulling the boat out of the water, we dunk the trailer to wet the entire bunk then pull the trailer...
There is a small piece that fits over the top cap piece at the front of the trunk locker. I will have to go back and look at how I built mine but if...
Rear seat is definitely able to be removed, the "back" of the bench is usually all wood, I think I have pictures in under my username of the rebuild...
While I have zero experience nor a need for what you are embarking upon, I am always curious how others solve various problems. If anything, think of...