The wheels are really the only place where you're going to notice weight savings for the way you're using that bike, and even there it's probably going to cost you a lot to get not much improvement. It looks like the 2009 F1X had 32H Mavic CXP22 wheels. You could save about 50 grams on each wheel by switching to Open Pros -- maybe more if you got something with lower spoke count. Your wheels probably weigh around 1800 grams. You wouldn't want to commute on wheels that weighed much less than 1700 grams. Lighter and/or better tires might be a good investment, depending on what's on there now. Of course, there's always a trade-off between flat protection and light, fast tires.
If you're willing to deal with the four pound rack and trunk bag, anything else that doesn't rotate will be minuscule by comparison.
I say just enjoy the ride.