Re: Padmé dying during childbirth and Anakin going dark...a causal cycle?
We don't see her buried, and Leah as vague memories of her mother as sad and beautiful. For the sake of plausibility, I assumed the emperor lied about her death to claim Darth for himself knowing his bond with padme was no longer a useful tool and rightly guessing that he would bond as strongly with his children as he had with his wife and mother before them.
It would not be beyond Ben to hid the mother as long as possible, if not as a friend then as a possible chance to bring Darth back and set things right.
There are lots of reasons a woman may die in child birth. If the emperor needs her to suffer or die for any reason he could make it so.
I felt Darth's progress to the dark side was well mapped out from episode one. It is his possivness and in felt with abandonment issues that drive him to form the bonds that drive him to make choices that ultimately hurt those he feels most passionately about.
The cycle is not what it seems. Its a cycle of self sabotage where the choices one makes to protect the people one loves ultimately are the choices that lead to their distruction.