Basement foundation / Discussions

...basement in our opinion would be - a super insulated raft slab (frost protected shallow foundation) on top of which would be ICF block foundation. 

...Foundation: This concrete floor is not intended as a structural slab foundation. Should I directly design it as a traditional slab foundation? In this case, the thickness would be around 4-to-6 inches. Floor Sandwich Structure: I'd like to understand how the layers of the floor system should be structured for this part...

...basement for TOTAL cost. While i know SOG is cheaper than basement, i can do 750 sq ft on top of 750 sq ft basement with finishing in two years after concrete dries vs about 1200 sq. feet with SOG to accomodate our total needs. So my question is: is a 750 sq ft house on top of 750 ft basement cheaper than 1200 sq ft ho...