Good to hear you solve you two player light. For the other problems, a small tip:
b. For a good working counters clean your counters, because they are a part of the loop in series with your relays. If a 500-point relay gets stuck most of the time it will be a problem with the counters.
c. In the back there will be a Match unit. They are very fragile, and mostly are broken on the frame. If it is still working, you can manually operate them. If you have the machine in game over, you can test the lamps by turning the Match unit.
Succes