The safe way to do this is to put modeling clay on top of the piston and turn the motor over. I doubt changing the spark plug reach will matter much....
Your friend is correct, the idle ECU is missing. If you are happy with the way the car is running then leave it alone but the car is supposed to have...
The fuse block/relay area is also a common source of trouble too. The blades of the fuses can build up a layer of oxide and cause bad connections and...