The door ajar light comes on when the circuit finds a ground, i.e., the switches for the doors hood and trunk provide a path to ground when the pressure comes off of the switch. One of your switches (maybe the hood) may be out of adjustment or worn. A bare spot rubbing metal (door) would do the same thing.
I'm going to put two of your problems together because they may be related. Trunk release and ajar light. Early models had a push button in the left corner of the engine bay. It's mounted on the trunk wall. If, and it's common, the deck lid warps, it doesn't depress that little button for the trunk light.
If the trunk lid is warped or isn't securely held down, the trunk release won't work because the solenoid grounds through the loop mounted on the trunk wall.
To test the ajar light, turn on the ignition and then lift and press down on the left corner of the trunk lid while watching the ajar light through the rear window. To test the solenoid, put some weight on the rear center of the deck lid then press the release button to see if you hear it click.
I just had this same issue. Mine turned out to be the pin switch on the rear hatch. For a temporary fix and to trouble shoot, I simply unplugged it. Then replaced it when the new one came in. The old one was worn internally and making connections for the ajar light. It would blink and would also illuminate even with the car off.