Start by picking one symptom and work on that. Here's the list from your first post.

For the first symptom, here's the circuit to inspect and diagnose with Alligator clip jumper wires.

By the way, the schematic from IPDB is marginal. Can somebody get me a better PDF copy?

Pinball (resized).png

Thanks, oldpins for responding to my request and sending me the schematic. Unfortunately the schematic you have is exactly the same as on IPDB, here:
https://www.ipdb.org/machine.cgi?id=438
along with the manual and other game documents

If the Credit button doesn't activate the Credit relay, inspect and diagnose this circuit with Alligator clip jumper wires.

Pinball (resized).png

In between there's a switch on the motor and one on the Reset relay.

But that doesn't matter.

Do you know how to use Alligator clip jumper wires?
http://www.planetimming.com/Pinball/troubleshooting/EM%20Troubleshooting.pdf
http://www.pinrepair.com/em/index3.htm#features