4130 is fine steel. the crank is pretty standard. The brakeset is nicer than any other stock bike I've seen (which generally have the cheapest tektro stuff they can get). If you don't like the color combo, you can probably find someone to snap up those wheels and crank for enough to get you some replacements. I personally think the green/khaki is a good combo. Some silver wheels would set it off nicely.

The headset will probably go in a year or so. Replace it with a 105 and you'll be set.

Also, good work on getting having insurance with a low enough deductible to get you a $600 bike. Must be nice to have hat kind of piece of mind.