CP, you did a LOT of extra work there. But really if you look at the weight of shifters, derrailleurs, crankset rings and rear sprockets and shortened chain removed we're talking MAYBE 2 lbs to swing over to a single speed. And more likely 1.5 to 1.7 lbs. In the grand scheme of things this is pretty much didly when we look at the weight of the bike and rider.
But I do agree that if it's done as part of an overall diet to the bike then some good things can result.