30 days is a little over four weeks of "Testing" (Sprint's Return if you don't like it window)...
How many weeks do you need to see if your problem multiplies? Looks to me like a legitimate nick, maybe an accident by the manufacturer, I doubt that random spontaneous pockets will continue to appear in the chrome without further use and abuse...
If you worry about the chrome, do you believe that Sprint will replace it for you after your 30 days or with insurance? What happens in eight weeks, or 52? Will the phone looks so bad that you can't look at it anymore? Should you not own the TP?
Have you considered getting Invisible Shield to protect what chrome you have left?
I have the Sprint Textured Black phone cover, and it covers all the chrome, so I never see it anymore...
http://nextelonline.nextel.com/NASAp...oryID=ZCH6855R
Good Luck!