Slab on grade addition adjacent to full basement – insulation and vapor barrier questions – GreenBuildingAdvisor

I’m building a small entry addition adjacent to an existing building with a full basement.  We were going to do a crawspace under the new entry, but discovered a large existing (12″ thick) shelf wall adjacent to the existing foundation wall (presumably built to support a stone wall above that is now gone), so we are switching to slab on grade.  

QUESTION: Are the attached details the correct approach, in terms of insulating the new slab and the location of the vapor barrier? Any thoughts/feedback would be most appreciated.