I am pure traditional(masorti) jew, israel passport holder. 1) May I live in Egypt? 2) is there pikuach nefesh in a) egypt b) Sinai? What do you think about it in general?

The Torah prohibits living in Egypt. As you are aware many communities lived and flourished there, and there is much halachic discussion why this was permitted. Most answer either because living in Israel was impossible in their times, or because they were living in Egypt temporarily. There are some reasons that do apply in your situation, but I would not encourage it.