Insulation, Radiant and Vapor Barriers - Crawl space & attatched basement ???

I have an unfinished basement that I have access to from through the garage. Connected to the basement is the crawl space. The basement and crawlspace are not seperated (they are ajoining with no doors). Concrete walls and no insulation at all. The above floors are cold. So the energy inspector recommended: insulate floors in the crawlspace area and close it off to the basement. Also need to insulate the ducting in the crawlspace area. no pipes in that area. For the basement (which has some ducting, all water pipes, furnace and water heater) he said to insulate the walls. Does this sound like the best solution? Also would I need to insulate return ducting as well? Can the pink foam boards be installed on unfinished basement walls without any protective (fire protection) cover? Is it better to do the walls or floors in the crawlspace? Thanks

go read
http://aboutsavingheat.com/crawlspace.html

http://www.advancedenergy.org/buildings/knowledge_library/crawl_spaces/

http://www.eere.energy.gov/buildings/info/documents/pdfs/29238.pdf

6 mil poly on the ground over lap it 2 ft. 2" or 3" insulaon the wall up to the joist .Blocks of R 19 insulation up on the sill plate in all joist all around the home. No insulation on the duct. We even cut in a register to let heat out and AC down there. This lets it all work as a heat sink for the home. Do the walls not the floor for insulation