Question: Why did Erle try to kill himself?
Question: How can Michael recognize Laurie as his younger sister since he wouldn't have seen her since she was only two years old?
Answer: There is a scene where Laurie dreams about meeting Michael as a young teen. It's unknown whether this is an actual memory of real events, but since nothing indicates otherwise, we could assume the he saw her at an older age when she looked closer to her 17-year-old self.
Question: Evil tells of his assistants, "tell me about computers". And he later says, "show me subscriber trunk dialing". Why does such a powerful entity have an interest in technology? (01:30:45 - 01:31:35)
Answer: Remember his whole speech about technology being his version of the universe, while the Supreme Being concentrated on nature?
Question: What was that first body in the woods that looked like Muffin? It couldn't have been Muffin because she shows up at the end right?
Answer: It never really says what the body is, but I'd assume it were a rabbit or some other small woodland creature. It can't be Muffin because, like you said, Muffin appears later on.
Question: Why does Ann blame Ginny for her mother leaving? She should be angry with her father and Ginny's mother.
Answer: Like all spoiled and mean girls, she blames everyone around her for her problems, when in fact it has nothing to do with her. She wants what she wants, her perfect family with her as the center of attention. The only daughter.
Answer: He hated the way they were living. Acting human, hiding who they truly were, integrating into "normal" society. He wanted to be wild and free. When they were feared and worshiped.