So i need to insulate my crawl space. i have a dirt foundation with several pillars supporting the house, (vapor barrier over the dirt), walls ave plywood with r19 blue board Styrofoam, trusses are about 2 feet below the ceiling(floor of 1st floor) 24 inches apart, vents in walls truss at mid truss level. ventilation for hot water heater and furnace are through the 1st floor from the crawl space. Currently when the furnace fires it sucks in outside  into the crawlspace and up to it to burn. This freezes the 1st floor floor, (triggering the thermostat after a couple minutes, drawing in more cold air, and que continuous furnace running during winter here). Pipes for freshwater and waste water run in teh middle of the trusses(except where they go out of the house into the ground).

my plan is to get a large quantity of styrofoam boards (the kind coated with foil on both sides), some "great stuff" small gap type, 3 inch screws with washers, a couple rolls of fiberglass batts(unfaced), and some HVAC pipe with 90 degree bends.

I intend to run the HVAC piping from the intake vents to below the level of the trusses, and run two large pipes UP from the crawlspace into the furnace room(for combustion air) this will help with a potential lack of combustion air. The walls at levels above the bottom of trusses  are to be insulated with the unfaced bats(prevents moisture problems). The trusses are to have the foil covered styoafoam attached to the bottom in a continous sheet(sealed with great stuff at joints), and sealed around the intake vents. see diagram(if i can get attached

Diagram

Sounds like a good plan.  You might also want to consider adding one or two supply and return vents(Depending on the craw space size) to the crawl space.  This way, that space will become conditioned and alleviate many of the problems of having an unconditioned space right under the house.

the area directly below the floor will be conditioned by the leaky air distrubution ducts/ radaition from them, the area under the styrofoam will be un heated(but i will have insulated against that with my styrofoam insulataion).

also the wife doesnt trust my plan becuase im not a contractor(DUH if i was it would be 900% over budget and not done till next year but the house would have an extra bedroom/bathroom...), what is anybody's qualification who comments that it is a good plan?