You didn't mention the make of the boat. Some models have known issues with gelcoat, the Sabre 362 being one. The original gelcoat was too brittle and applied too thickly. The result is a lot of cosmetic gelcoat cracks.
Most of the cracks I saw in the photos were in areas of a tight radius, this is a difficult area to build. First, fiberglass does not like tight bends and corners this often causes the glass to pull away from the model to make a more gentle bend. This causes small voids to form between the gelcoat and the glass. Eventually the gelcoat cracks and chips out. It is entirely cosmetic as gelcoat is not at all structural. The repair is easy but time consuming; clean out the void, fill with thickened epoxy, fair and paint or gelcoat.
The other big cause of gelcoat cracks also happens in tight corners, gelcoat (and all resins for that matter) are quite brittle unless reinforced with something. When a deck is popped from the mold, it is sometimes uncooperative and excess force is applied to some areas, this stresses the gelcoat and causes cracks to appear down the road. Again, it is a cosmetic issue, not a structural issue.
And then there are the usual chips and dings that occur on a boat over the years, these are the patina of use.
The water stains. The sole outside the head is water damage. Since it is fairly limited in area, my guess is that it came from sloppy showering, wet foulies, and spray from the cockpit. It has a pretty defined shape that would match shower overspray. It also looks to be near the companionway, another innocent source of water.
I'd want to take a good look at the vertical areas that have the whitish cast to them. There is a form of mold/mildew that is white and it doesn't take much to get it to grow. If you look at the boat again, take a damp rag or paper towel and wipe the area in question, if it is mold it will wipe off (this won't cure the problem, just takes away the most visible mold).
Unless the boat has been given an exceptionally long time to dry out, if it has been seriously flooded and left flooded for a while the humidity in the boat will be palpable. The wood will feel damp, the cushions and fabrics will feel damp and smell musty. If you have access to a moisture meter the wood will have a high moisture content.
As
@capta mentioned look for evidence of delaminated plywood. If the plywood is wet it will delaminate and eventually need replacing. However, if the boat is not stick built and has a fiberglass pan, the sole is less of a concern as the fiberglass pan is structural and the plywood sole is cosmetic and easier to replace.
I'm not sure what to make of the nav station. It could be the table top was suffering from the patina of use and it was in the process of being refinished, however, if it was being sanded the bulkhead behind it was sanded in a funny manner.
The motor mounts are rusty, however, they are steel and sit in a humid environment. The rest of the motor looks pretty clean. They may need replacing, but I don't think they lend much evidence to the massive flooding theory.
The key here will be finding a surveyor who is competent and one you can trust. Good luck on that.
