Do you mean the flap has become detatched from the bonnet, or the cap doesn't fit? With your vin, you should have a lockable cap, and the spring-loaded flap in the bonnet.
1. What is the preferred method to re-attach the gas cap? It looks like the epoxy cracked that held it to the hinge.
Oil, battery, fuel (if low), all of them, basically.
2. If the key is turned to the 'on' position without the engine running, what instrument panel lights should be illuminated?
No. You need to adjust ht elink-rods in the door. There's a procedure i the updates manual.
3. Will a Lockzilla fix a door lock that sticks in the 1/2-way position?
You have OEM regulators and the teeth have been chewed off the drive gear. Ther are stronger replacements available.
4. It seems like the passenger side power window, when closing, attempts to 'over-crank' after it has closed and makes an awful noise. Any idea what this could be?
The luggage compartment is workign fine - the later cars had a stronger spring in the latch so the bonnet goes "pung" on its own when you pull the lever, but yours won't. The engine cover should latch shut,but the louvers freely move.
5. I've read the owner's manual, but I'm still unsure how the luggage compartment, and engine compartment release levers are "supposed" to work. My engine compartment lever does not seem to do anything; I can lift and lower the louvers and compartment covering freely. The luggage compartment, I need to pull the lever and at the same time pull up on the hood to raise it.
Martin #1458 (close to yours)