Thats not from oil....i guess it is from the heat.
Whiteish look is ok....good combustion sign.
'94 T5 could run a bit rich or driven on short distances and that's why they are darker.

About cap & rotor...Swap it from '94 T5...they are the same.

Swap the whole thing...along with wires.
It's easier.

Great!
Problems troubleshooting is much easier when you have almost identical other car to swap out parts from it.

Possibly a SAS valve is not working properly. Misfire codes and actual misfiring and flashing CEL(when misfiring starts) can occur if SAS valve is not closing when it should,allowing moisture and water from condensation to be sucked into engine via air filter housing...instead of going through exhau...

General rule is...the numbers from original TCM needs to be exactly the same on the replacement TCM,excluding serial numbers. In your case....TCMs have different part numbers and different software numbers. One is from '97 the other one is from '98(according to serial number). I would not try to swa...

It's not the battery or abs module...they have nothing to do with this problem. Because...even if the battery could be low....the car cranked,started and ran.As soon as it started the alternator started with charging,supplying the consumers with proper voltage. Could be connectors at instrument clus...

Time to check main fuel injection relay...grey one on fan shroud.

That's probably it.
Summer tyres gets hard at temperatures below 7-8C Celsius...and 50F is 10C(according to conversion table).

Down and AFTER the Maf.
Closer to throttle body.