Please relax about Sedom. Avraham Avinu did not interfere. He prayed. And once he was told that there are no righteous people there, he stopped praying.
It was not up to him to judge or punish. He did his part, to seek kindness. Hashem did punish them, and we learn from that as well. In fact, Avraham went to watch the punishment, being such an important lesson.