Well of course one has to be careful not to play into the theist’s hands. Which is why it’ll be obvious that the characters are flawed. It really should be obvious from the fact that they make concrete plans to kill people…
Theists will see them as perfect examples of the typical evil rationalists, but there’s really nothing I could do against that. (Even if it were made very clear in the film, they would just re-edit it…). So I don’t care about that much.
As to your hope of failure, it probably will (mostly because I’m a rubbish writer, don’t know any passable actors, and don’t have any money)
Brilliant!