Hmmm, the idea of pouring insulation in is certainly intersting. What about removing the ceiling pannels, pulling out the insulation, re-installing the pannels or use plywood then inject the liquid foam into the ceiling? I love the idea of it creeping into all the little cracks and crevices. Or mabye it would be a rotten pain in the ... well, it could go wrong.
For the flooring I am thinking about using this product -
and search Refletix
(sorry I tried to place a link but was unable)
The thickness would not be as much of a concern as say 1" foam insulation.
So I am thinking of taking it right down to the metal, Laying 6 mil poly, then installing ribs 1/2" with insulation in between, then laying laminate "hardwood" flooring in. -Richard