I'm with RVecc on this one. A carpenter told me this and when the carpet estimator came to give me a quote he said his installers would be very happy with that. I believe the trim is more like 1/2 to 9/16 of an inch. It's nice to put the carpet down once most of the dirty work is done so you don't have to protect it. Installing the trim after the carpet is fine also.
Not really my area of expertise but if you need to scaffold the Washington Monument or install security bollards I can help.