I don’t know if you answer these kind of questions, but for many years I have always been perplexed as to why Avram was afraid of being killed by the Egyptians, since obviously he was not chayav misa b’dei shamayim chas v’shalom.
The same thing later on with Yitzchok and Avimelech, and later with Yaakov and Lavan, and especially Yaakov and Esau where Yaakov took special precautions and defensive measures, also Esau sent his son Eliphaz to kill Yaakov, and later of course when Yosef was put into the pit of snakes and scorpions to save him from being killed by his brothers.
Obviously, these were the greatest Tzadikim of all times, and were not chayav misa b’dei shamayim chas v’shalom, so why were they so afraid of being killed?
You are asking a good question. What we see from your observation is that the tzaddikim, no matter how big of a tzaddik he/she is, never trust themselves, that they are truly righteous, without any Aveiro whatsoever. The Gemora (Brachos 4a, Sanhedrin 98b) asks, how could it be that Yackov was afraid of Eisav, Hashem told him (Bereishis 29-15) that he will protect him wherever he goes? He Gemora answers that he was afraid that maybe in the interim he sinned, and therefore he was afraid. The Bartenura (in his commentary on Chumash Bereishis 15-3) says the same thing about Avrohom. Additionally, the bigger a tzaddik is, the closer he is to Hashem, and the more he realizes how much more kindness Hashem has bestowed upon him, and how much he owes Hashem. Therefore, he is always afraid that he possibly has not done enough. Besides, the bigger a tzaddik the person is, the more Hashem stringent Hashem is with him, to make sure he is perfect, therefore he might get punished for a minor mistake, in order for him to come to the next world totally clean.
Therefore, although they were the greatest tzaddikim, they were still afraid.