Okay, concerning "The Secret Messages". As this is the opening task and was designed to be incorporated in every route possible, any cross at any local church will do. And as a GM I will now use my powah to patch the rules (behold!) and add that any photo of Jehova's Witnesses taken IRL will count as a Morninglight reference.
As for myself, I decided to take it to Nightmare level and persuade Jehova's Witnesses to say "Hiya, Chuck!" on camera but failed so far. They said that Jehovah doesen't forbid those words but they're just not in the mood right now. It's a pity that I wasn't documenting that on the video, because when I came to them and asked to talk to the camera they said that they would like me to study Bible. I said that I already know Bible, now it's their turn. And so we argued for ten minutes or so, ending with the conclusion that they, as a simple mortal people have their flaws and therefore won't do me this favor.
And I'd like to remind that you don't have to do the tasks in order (this time), and there are plenty other in-game tasks to fill the gaps.