(1) In the CL section, you changed the distance from electric lines TO 50 feet from OVERHEAD electric lines FROM the current 50 ft. from any electric line.
IMO that is a BAD change. That electric line over to the side will kill one just as fast as an overhead line maybe more so because the line to the side is the line that will get the guy that is running backwards to catch the line-slack when a model inadvertently turns inward.
I read this to mean that there is no need to maintain clearance to underground power cables. The "overhead" refers to all above-ground lines in the vicinity, directly above or not. Still, if one person came up with a different interpretation, others will.