I'm really not sure, could be something with your Immobilizer, as you mention the car turns over but won't start. I don't know why the hazards flash when you turn the car on. Maybe 2 separate issues?? I've looked over a bunch of the circuit diagrams for the car, here's something you could check, but honestly it's a long shot.
I noticed that the 50A BATT Fusible Link which protects the alternator, also provides memory power to the immobilizer. So what if that Fusible link burned out the last time you were driving. I think this would cause the Alternator to stop charging the battery. So you get home with the battery almost dead, next day car won't start, replace battery, still won't start, as that Fusible link is burned out, and therefore not providing power to the immobilizer circuit in the BCM, so now the car won't start because the immobilizer isn't powered.
The 50A BATT Fusible link is in the Relay box in the engine compartment (right side in the center). There should be a diagram in their showing the BATT 50A. Use an ohm meter to test.
Again, a long shot, but that's the best I could come up with.