The zombie talent doesn't make you a zombie, it solely changes elementlal and healing interactions ; it does not set you to rotting or make you have a need for brains / flesh, or slow your gait as your muscles wither and your blood hardens in your veins.
Meanwhile ; not all of the undead you can battle in-game have the zombie talent - that is to say that there are actually some undead in game who are not harmed by traditional healing and are not healed by poison.
