Pictures?

Wall sheathing and a vapor barrier are not required unless you instruct the contractor to install them. What were your instructions?

None of that is required for non habitable , non conditioned spaces. Insulation is virtually worthless for non conditioned space. A “pool house” is just your shed, tarted up a bit, for a place for people to change. That’s it. If you wanted a habitable space, the design and permitting for something like that is quite a bit different. And the shed would likely need to be a 100% rebuild to higher standards.

Who did the design work for this project? What were the specifications? What kind of design documents was filed with your municipality? What permits were pulled? What inspections have been done?

Have you check with local zoning restrictions? The change in the structure's use may be an issue.