Well let me start off with the gauges. YJ all gauges are broad estiamates. Fuel guage problem can be solved by dropping the tank and cleaning up the contacts in the pick up in the tank. For the blinkers you should dismantle the stearing column and it might be wires getting streached, or coming lose. Over heating, whats the temp say? Jeep engines run hot my 4.0l runs at just over 210. If its more then that check fluid, t stat, and try a radiator flush. Not sure what part your talking aboot on your air box, pic would help. Last your door is probaly out of adjustment, but check that the latch is latching first befor adjust it.