Ignore the soft spot. Probably a knee bump or a knock on the trailer that broke some fibers or compressed the foam. From your description this is not in a stress area. So if there is no water getting in it's not going to move. Just ignore it.

For the crack check that it is airtight by aiming the output of a vacuum cleaner toward the bung hole (*don't connect the two, blow from a distance*) and dropping soapy water in the crack. Bubbles = problem!.

If it is airtight, dry it up, tape it and go sailing. At some point in the future call the builder to get a little bit of gelcoat in the same color, remove the crud around the crack, fill it with new gel coat and fair it up. Done.

If it is not airtight this could be more involved as this would indicate that the two hull halves are separating there. It is unlikely however. My guess is that a bubble got trapped under the gelcoat and it just cracked from fatigue.