Could you please provide a parts list? The weight of your bike is incredibly low. I was looking for light parts for construction, but I have 1 kg more weight than your bike.
If the BMS is operational, it protects the maximum current. If the BMS breaks down and causes a short circuit, the fuse on the red wire does nothing.
I have a charging protection on the charger cable, you don't have to put it inside the battery. You can also protect the motor-battery...