That is correct that only the stop and tail lights were fused. This is probably because they were located in the rear and thus were most likely to be shorted out at some point.
If you look at the design you will see that they have tried to give reasonable protection along with some safety considerations. You don't want a fuse to kill your motor in the middle of the road. There is a thermal breaker in the headlight switch that covers the headlights and some of the dash features including the dash lights. I believe that the ignition circuit is not protected but I could be wrong there. Also, the thermal breaker activates at around 45 Amps and there is plenty enough energy at well below 45 Amps to start a fire so having wiring in good condition is pretty inportant.
