keep in mind the FDA also approves prescription drugs that end up being pulled after several years because they killed too many people. any drug will be FDA approved if the lobbyists pay the right people.
anyhow, since you are shy a kidney, I would probably either not take creatine, or more likely, take no more than 3g doses. creatine itself is NOT hard on the kidneys. excess creatine is, because it degrades to creatinine, which your kidney will have to strip out of the bloodstream. creatine isn't a 'necessary' supplement anyways.
protein powder should be fine, simply drink plenty of water.
the only other supps worth a damn are a multivitamin and fish oil caps for the EFA's. nothing fancy at all.