Sounds like two unrelated issues.
1) Coolant is OLD and you need to drain, flush and replace... don't forget you must use "no phosphate" coolant!
2) Oil on clutch. Replace clutch and figure out where leak is and fix it (engine main seal most likely but could be transmission input shaft seal).

I would check these things;
1. Does the fuel pump have enough pressure? It should have 2.0 -2.5 bar (29 - 36 PSI). It is located on the frame to the left of the transaxle.
2. I would just go ahead and replace the two relays in the little (5"x5" ?), black plastic box on the left side and above the motor. These are your main power and fuel pump relay. They can be quite trouble some and cause similar symptoms.
3. Check the ground for the ignition distributor. A little brown "pig-tail" wire. Should be grounded to the crankcase vent. Make sure it has a good ground. Also the cluster of grounds between the upper rear left head and body. If you said, checked some grounds, but take them off, clean them, and secure them.
4. Air flow meters fail fairly regularly on these and should have the retrofitted "diode harness" plugged in between the meter and harness.
5. Check the throttle position switch under the throttle body. The switch should make a "click" at the idle stop and another "click" at full throttle. Remove the throttle body if you need to make adjustments. Sometimes the butterfly shaft gets worn and you can not get the switch adjusted to make both "clicks"
6. Check for burned wires at the back of the fuse box, and "fried" connector pins.

A couple other things, at this point I would also;
1. change the coolant temperature sensor (blue plug near the thermostat).
2. drain cna fill new coolant mix.
3. can you get a hold of another air flow meter to try?
4. lnspect the fuel injection control unit, try dismounting it and shaking it or changing it's position.

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