It does look like it's forming balls, is it meant to be feminised? You can leave it a few more days to make sure. I can't see any pistils, and if it's showing it's sex before all the other plants, it's probably male, not hermie.
About your original question regarding the watering of the coco, you do want to be watering every day, but this MUST be done in the right size pot, when your plant is too small for the pot you need to wait for the moisture content to drop in between waterings instead of just feeding every day.
You're right that the ec and pH does change too much if you let it dry too much, but when your plant is undersized for the pot, the moisture content doesn't change much in 24 hours, so that's why your plants looked overwatered, because they were. When you use coco you should use smaller pots than soil and you should transplant frequently into only a small step up from the last size. This allows you to keep feeding very often.
Your question about too much light... there is such thing as too much light indoors, that's why we have to raise our lights to a certain height above the plants. I think the general rule is that you want something like 40-50w/sq. ft for bloom if your lights are reasonably efficient, and the most efficient lights can be spread out to about 30w/sq. ft. How big is the area your plants are in?Here I am sounding like a know it all again but I don't mean to sound pretentious, I'm just relaying the knowledge I've learned, a lot of it gained from all the wonderful contributors to this forum.