Have you considered just going with the basic circuits required for it to run and working from there to find the problems? I recently brought home a LA110, that had severe mouse munching on the wiring and the previous user had bypassed ALL the safety switches, relays, etc., to make it run. It was a nightmare to get back to stock wiring, but at least it ran when I got it. You had to choke it to kill it, but it ran. I'm guessing the wiring issues you are running into are because one, or more of the safety switch circuits failed and the previous owner tried work arounds, that didn't work. The voltage regulator over heating may also be from a grounded wire in one of those safety circuits, that is not supposed to be grounded. The ground that runs to your ignition switch is to kill the magneto, when the switch is turned off. When that was missing from my wiring, it was why I couldn't turn off the engine with the key. Good luck with you wiring project. It's lots of fun.