Much of the over watering problems and too moist soil may very well come from the fact that your plant looks over potted, meaning that it is planted into a container that appears to be too large for the plant. Perhaps you could try re-potting into a much smaller container, making sure that your potting soil is a very coarse mix, and see what happens. Mind you, water thoroughly on watering day, but then let the soil dry out until the next time.

Hair spray actually used to be dangerous. The propellant used was vinyl chloride. It was hardest on barbers and hairdressers since they were around it all the time. The danger was a significantly increased risk of liver cancer. I think the show I watched was called the Chemical Revolution. There was also something in maybe the hair dye?? that caused a surprisingly high rate of bladder cancer in hairdressers. (Obviously this is not a commonly occurring cancer.) Here is a link that might be useful: PBS link about Hair Spray Propellant

Fruitless (male) mulberries were very popular in our neighborhood when developed during the late 1960s. A few are still doing well, but most declined in the 25 to 35 year age range. Can be a very nice fast growing shade tree, but here are a few comments after living with a couple of them in a small yard for over a decade: Three feet from the PL could be tight if there is a fence or other hard-scaping - Trunk will eventually reach ~3 ft in diameter plus another foot or so for root lift around the base. Our PO planted one only about 7 ft from the house slab. While way too close for its eventually large trunk, the roots didn't cause any foundation or drain problems. "Fruitless" does not mean "flowerless" - The male flowers are numerous, large, and produce MUCH pollen. Not bad over a lawn, but can make a mess over vehicles, pools, gutters, or other spaces where the piles of flower debris and/or yellow dust would be a problem. As mentioned earlier, seems your neighbor's could still be an immature female tree, then would also deal with the fruits. They grow fast and want to branch low and often. Makes them wonderful climbing trees, but can require more trimming (large + fast growth) on urban lots than most others. Removing new whips a couple times a year while still small enough to be clipped with a pole pruner was much better than fixing the frequent crossed and sagging-towards-the-ground branches later with a saw. They want to produce very dense shade. More shade tolerant turfs, like St. Augustine, can be kept alive to within a few feet of the trunk with the right exposure and pruning. May not be much of a change factor if the tree is to your north. But if it's on your south that close to the PL, it could eventually change what can grow in something like a 18 foot arc of your yard. Not necessarily a bad thing. Assuming you were diplomatic in asking to kill you neighbor's tree, seems unreasonable for them to get angry over your concerns about such an eventually large and rampant grower that close to your PL. Maybe there's still a window to suggest/offer moving it or replacing with an alternative better for both of you in that location.

Well, beans (pole beans, mainly) and squash are two of the three sister (corn being the third) so you could leave them grow. tj