"One thing I can say with certainty here is that the 120V string of lights above the pool MUST GO! "

I used to do electrical work. Changed out a box and subsequently they wanted me to bid on digging a ditch for power to the pool and garage because the wires were overhead at the time. I had to turn it down because it was just too much PITA. If they had called on me before the pool was in it might have been different but people do not think ahead. The job was bad enough, had to make a new hole for the mains, and it was right in the corner so had to cut the cover side off an inch or so. I hope they got it done. Thinking about it, if one of the wires, even the hot fell into the pool they would be alright until they tried to step out of it. If there was a load and both ends fell in, ZZZAAAPPP. If both wires fell in from the fed side also ZZZAAAPPP.