Jim,
A long distant guess but everything you describe is "GROUND(S). Either not enough proper grounds or simply a loose ground. Do you have a braided dedicated ground from the engine to the frame? Are all your grounds piled on top of each other? Break them apart and use more grounds to the frame/cowl bar. Do you know if your cowl bar is welded to the frame of did the builder only use the four bolts the book calls for? The starter button should absolutely have it's own ground with nothing more added to it!
If it was in the shop this is the first thing that I would look for. To much of a coincidence that all these components would have seperate problems!
Keep me posted-hey?
Ed, thank you but I think I will attack this thing today and see if it really smokes! Then we'll see!
DV