microswitches can be a problem.
iv just got my boot light working accidentally while changing my tailgate, i think the microswitch connector wasnt making good contact on my old tailgate.
your rear washer. take the pipe off and have someone operate the rear washer n see if theres any water coming through, if not its blocked.
theres a connection from the pump on the washer bottle in the engine bay that goes into the inner wing and to the rear, i noticed mine had split just as it went into the wing

, helped that i noticed a big puddle under the car tho

.
might be worth giving your washer connections a good looking at.