First of all, the casset tape we see in TWF 2 says that jack dies first, but it's actually Edd and Molly who dies first, so maybe these were plans?
But unto some more stuff, when we see Bon in TWF 2, we also see that he has a huge hole in his chest. Now, lets say for theorizing, he had a body in him, such as Jacks. We would be able to see that. Why can we not see that here? Its simply because bon is only temporary used as a suit. Here's what I think happened (events)
So Felix first kills Edd and Molly on accident. He's worried Jack will find out, so one day while he's possibly working, he kills and hides his body. Sophie was maybe forced to help Felix, and so she helped lure Rosemary and Felix killed her. Sophie walks in and is then forced to take pills, so she never remembers this. Susan notices something off with bon (Felix also was suspiciously "not there" that day) and tries to fix him. Felix kills her, because if she knows everyone may soon find out about his past. Charles is still unknown, but after this Bunnyfarm is played. Felix is now after Sophie, because if she knows, word will get out. He's most likely sucsessful in this, as in the S1 trailer we see Sophie on a poster with a date below her, so she is either missing or dead.
If I missed anything please ask or correct me!