1. Yes. There is zero precedent for a throuple ending from a DPC game.
2. In first DnG, MC only dies if he tries to protect Jill. That's also called foreshadowing. Unlike in first DnG game, Josy always dies in second - no matter what.
3. Yes, but in the context of Zoey he was telling Bella a specific story. This entire game is MC's recollection of an important time in his life, and he starts with Josy. There must be a reason for this that ties into an unavoidable plot element. I say that foreshadowing and precedent indicates this involves tragedy. (PS - and that tragedy involves Bella chopping off Josy's head with the axe in her garden shed after she catches her trying to pull an Ocean's Eleven to get the MC and Jill into her secret locked room)