charging issues
The main things that cause a severe overvoltage/ overcharge such as this are:
Bad regulator
the voltage drop problems that I"ve mentioned in the harness and ground circuits
The "green" connected brush being grounded, IE the blue field wire, being switched ignition, then feeds "full field" to the alternator = full output all the time
Sometimes a bad battery
Your coil / and or ballast may or may not NOW be damaged, but given the symptoms, I'm sure that you have an overvoltage problem, causing the ignition to draw excessive current. You may be overthinking the ballast--they DO run hot, too hot to touch.