Wow... that's a mouthful.. are you sure you're not leaving something out
The Brake Icon: Is that brakes or ABS? For ABS it's most likely a bad connection at a wheel sensor, or bad wheel sensor. For brakes, you said the rears are new, take it back to the place that did the brakes, they don't have the rears adjusted properly.
The Suspension Compressor will run every hour or so for after the key is off. This will stop after some period of time, I cant remember the length, less than 24 hours.
Another thing I don't get, sorry
After the suspension pumps up (approx 10 miles), the the fault lamp lights, I don't get why it would ride differently, unless the rear-end vents and starts dragging on the floor.
On that subject, you need to determine if the rear air springs are leaking. If so, the compressor will overwork, warnings will come letting you know of a problem. Ignored, this will cost you big bucks later. Nip it in the bud and you have many happy years on the air ride. A basic test would be to shut off the air ride (switch in the trunk) and see how many days it holds up. BTW, a competent mechanic MUST shut off the air ride system prior to lifting any part of this car. The system should hold to the same level for a week or more. Any less indicates leaking springs, valves, etc.
The headlight switch in the 1996 is a problem.. well, actually its the circuit. We have the full load running through the switch which makes it overheat. This causes dim lights and other problems. Most folks that experience headlamp problems ADD a relays (hi and lo) to the circuit to remove the load from the switch. Gives brighter lights, and fewer problems. Other problems with this circuit include the MFS (multi function switch, BOO (brake On/off) Switch, and lastly the LCM (lighting control module).
That voltage drain is puzzling. Is there any obvious sources of voltage drainage? You mentions "lamps all over the place", are those staying ON?
The most common cause for this type of problem is a bad Alternator, well it's actually the diode bank in the alternator, that bleeds current to ground. That whole "remove a 15A fuse stops the drainage" is puzzling.
The CEL (check engine light); you must have had someone read the DTC's for you to determine that it's the "exhaust gas re-cycler thingie under the TB", was there any other DTC's? Hows the engine performing?
I ask that because our 1996's don't usually have EGR problems till we hit 100k / 120k miles on the odometer. Oh, BTW.. how many miles on your 96?
Are you going to be working on this car or do you have someone else take care of these things for you?