grounding question re: the neg battery cable

"VERY important that the body/ frame and block be well tied together, especially nowadays with all this electronics. Electrical "noise" can cause all sorts of problems in all sorts of equipment, ignitions, computers, etc, as well as the age-old problem of the regulator putting out too much voltage because it does not properly "see" the battery"

2 more questions:
-from what you are telling me if the smaller no 10 gauge ground from the battery to the frame is not there, this will affect the voltage regulator. If the voltage regulator puts out too much voltage how does that effect the coil?

my engine does not have the third ground from the block to the frame. How does this connection help?

thanks so much