Verify the floor condition by looking inside the cabinets and benches around the perimeter of the trailer. That's where leaks from windows
are most likely to cause damage. The center part is usually covered with some kind of finish flooring, so you can feel for sponginess and look underneath for signs of staining. Beware of fresh laminate flooring; it may hide softness. If the floor is solid, resealing windows
and vents is not such a big deal if required. Excessive caulk is a good sign of issues. Caulk is a bandaid, not a fix, and silicone caulk is a nightmare to remove.
You are correct, the axle
is not an issue for towing as long as the tires
aren't rubbing (check clearance inside wheel wells). But bearings are. Sitting for a long time is not good- might want to repack before heading out.
Best wishes with your "new" Scamp!