I would prefer not to root it as long as there is a warranty on this device. And I know some of you saying but you can always flash a stock room using ODIN, but seriously guys if your device is knackered, is this really and for sure going to work before you can send into whoever?!
You are right 100%. If you are considering potentially sending a device in under a warranty claim, you should absolutely not root it. Doing so, if you should have an issue, is highly immoral (to file a claim after you knowingly violated the terms of the warranty you are trying to cash out on). This hits the OEM's checkbook and raises costs for consumers. Insurance is a very different matter, because you're paying for that on a voluntary basis per individual device and it's an insurance company that takes the "hit"; however both parties enter into that agreement for mutual benefit with the same understanding of trying to screw the other person out of a dollar.