Gentlemen
Unborn children are evil by definition. How many children must be taught to be bad. He should kill unsupervised waifs as no one can teach them to be good.
The thought for the day.
The slaying of the kobalds is purely dependent on the god our Paladin is following. If he is islamist the answer is of course they are not of the faith. If he is christian the answer should be the same in self defense.