Hanging it is an idea as well.
As long as I can make a frame to support the sides, fasten to the new floor/ribs it should be fine to set it down on that, instead of transferring all of the weight along the seam of the top and bottom. It will be interesting on how it will fit back on the trailer.
It would just be a bare bones hull and frame at that point, after pulling all the interior and engine and drive, cut out a lot of the weight as well.
As for the roller trailer this is the first one I've been around, both my fathers boat and my smaller one are on bunk trailers. It looks to me that this one is set up okay, but I am worried about it having dimples, pretty hard to tell how it is now. But the boat as been on the trailer for most of its life, be interesting to see!
More imperfections in the hull the slower she goes!