LYL:

You are indeed correct about the direction I was taking. The specified plugs are non-resistor. Why? The rotor has a 1K resistor, each terminal in the cap has a 1K resistor, and each plug boot has a 1K resistor. Adding ~5K more in each plug is too much; the required system voltage, the voltage to initiate the arc, is forced too high, and leads to internal leakage in the coil.

The cold drivability matter is likely related to delayed warmup of the O2 sensor, combined with a lean basic fuel meter adjustment.