Are Christian & Muslim morals based on the "might makes right" principle?

Yes. Biblegod is supposedly the biggest kid on the block so he gets to declare "do as I say not as I do" when he commits or endorses m murder in his "Word". As described in the Bible, he is a tyrant and an egomanic regardless of his claims of being "loving' and "just". Heck, the creation myth at the very start of the tale says all you need to know: God set Adam and Eve up for their fall, knowing full well what would follow, then blamed them for what happened. Some "love and justice".