Oohhh! You weren't exagerating when you said it was cracked!
Well, those bunks are definetely in the wrong place! The good news is; Looks like the cracks are not near the ballast tank. You might be able to see the cracks from the inside through the access panels in the aft berth. With luck, you might even be able to do the inside repair through those access hatches, though you also might have to cut the openings larger to work in there. Another bit of good news is that whatever you do will be under the aft berth cushions. The liner is bonded to the hull and I think that area is also. You might be able to play off that, get more support/bracing from the underside of the liner.
Great looking trailer, by the way. I'd modify the trailer first. You
can use bolt on risers just like mine,
easy! Looks like you need to cut down or cut off those welded on risers that are there, they look too high. But if you go with the welded on method, part of those can likely still be used. The cross members are in a nice vee already, I think you could set yours up just like mine!
Once you get the trailer right, hopefully the shape will comeback somewhat, you might have to use some wood bracing inside, glass it in, it likely will end up stronger than original. Once the shape is back, and it's done properly inside, it's just cosmetic outside, nothing some FG and gel coat can't fix.
I hate to say it, but looking at your straps, those are some big honkers, don't need em that big! Those are for heavy freight on a truck. And where they are positioned... Those strap winch handles are very powerful ones, you can easily way overtighten them. Kinda looks like that's what you did. Add all the water weight you mentioned inside, a bumpy road, bunks all wrong, and well...
Once you get this fixed, use some lighter straps. You only need to snug it up enough so the boat can't bounce around on the trailer. Once you get to your destination take them off. Even with relatively light pressure, if left on the boat all the time you can put impressions in the rub rail too.
Be careful, don't get ripped off, I think $5-7K is way too much! This can be fixed for a whole lot less!
Step #1 get the trailer setup correctly. Once that's done, the pressure will be relieved from that area, the shape may come back, things might not look so bad. This can be fixed!