Although I stated that he controls everything, I'm not sure he is responsible for Shmi's kidnapping. I don't think he has to kill Anakin's mother to seduce Anakin. It's just a bonus. The point of Anakin's mother death is to show why jedi knights train very young babies, and keep them away from their families. Anakin keeps thinking about his mother, and he's afraid of losing her. When that happens, he is unable to control his emotions, and gets mad at his jedi master ("it's all OB1's fault"). The jedi fail in their training of Anakin. Anakin is frustrated with his master long before his mother dies. Palpatine senses it, and he exploits it. He is in a position oif power, and he has very little to do to get what he wants.