I have been thinking about taking the gray plastic piece off the very bottom of the bumper (the piece that the tow hooks are accessed through), but I'm afraid of how it might look with the tow hooks just hanging out there in the wild blue. I want to take the piece off because I don't like how it looks. It kind of turns inward towards the front tire and makes the front end look like it's riding really low. I like the GMC bumpers much better. They're color-keyed and have fog lights in them and don't hang so low. Maybe I'll just look into swapping one of those on.

Sounds like you are referring to the front air damn.
Look underneath, there should be black plastic fasteners that attach it to the underside of the bumper.

There are a few aftermarket versions out there you may like instead. Checkout www.stylinconcepts.com or www.truckperformance.com :D

The GMC bumper won't fit on a chevy. The angle of the grille where it meets the bumper is different. The airdams don't interchange either.
The NBS trucks look like crap without the airdams on.
If you have a 99-02 you can swap for a airdam from a Tahoe Z-71. They have round fog lights and look different from the pick-up ones. If you have a 2003-06 you will have to go aftermarket.

This is actually called an air dam, and you owners manual shows you how to remove it for more offroad clearance. I think that they look bad with out them on. So If you want look at your manual and itll tell the proper way to remove it. Just my $.02