"*Is dehumidifier water healthier to feed to plants than tap water that has sat out for 24 hours? It would seem to me that it would be pure water... but I dont know."

Comes out at 0 PPM, so yeah, I would say it's alot healthier than tap water that has sat out. You can also buy reverse osmosis water from your local grocery store\water store for in between 30-50 cents a gallon - try that out.

"*Is there any reason other than luck, that 8/8 of my plants decided to turn female on my first grow?"

Lucky.