Seems the problem is when you have a hardware failure under warranty... Not only do they(of course) see all your non-sd data, but they might see it was rooted and refuse to replace it.
I'm going to have to call b.s. on you there, bob. Lemme guess, you work for Verizon? If one had a hardware problem, one would wipe internals prior to taking to Verizon. Also, when you turn in your phone at your local Verizon, they cannot tell that you were rooted if you just return to stock like everybody else said. Don't be scared.