Hi, I've had a look around and it seems fuse f8 does more than reversing lights. Try turning on everything in turn with that fuse out to see what its protecting...
I also had a current drain with the car locked, turns out it was Bluetooth module not shutting down...
Does yours have Bluetooth/hft? These are very well known to fail. In the accord the module is right behind and above the centre air vents, don't know if yours will be...