Kadaj of life, Loz of birth, and Yazoo of death. Wouldn't you agree their personalities seem very overdramatic?

Did it say somewhere that Jenova can't replicate its own cells without another living organism to corrupt and transform?

Why does Jenova have a woman's form as Synthesis? Is it to live up to Sephiroth's delusion that the J is his mother? I mean, it is under his control, right?