Yes try all new leads, it's something that should be done anyway.
What a dilema!

Inside the distributor there is a an inverted "can" or disk with 4 cutouts in it. This sets up the timing pulses through the hall sensor to the ignition computer. Make sure it has not slipped or come loose. If it slipped the right amount then spark could come when the rotor was pointing away from the output thingies to each wire.
Another idea: Is it possible that you have a weak power stage that is not fully driving the coil?

Don't think that the key problem could be related.

BTW I have read that it is best to check for spark with an old spark plug held to ground because other methods may damage the electronics. I have never had a problem though using "the old screw driver up into the plug cap and see how far the spark will jump" method. How far does the spark from the coil jump?