I don't know if the sky is falling, but if it were mine, I would definitely address the issues. Not sure what to say about the potential delamination, it's pretty hard for us to say just from a verbal description. You might have a reputable repair shop look at it and give their opinion.
As for the floor being soft, that is a problem, and you need to find where the water is coming from. Is it a leak where rainwater is getting in ? Is it from a plumbing leak ? Or has the under belly been very wet to the point it has rotted thru from the bottom ? What ever it is, the source of the water needs to be figured out and solved, then the floor repair done.
I would inspect the roof very carefully.... inch by inch to see if there are places where it is allowing water in.
