First question - This all depends on if it was a true hermi or a stressed female. If it was stressed due to enviromental conditions and noob era and the other plants are in the same conditions the chances are pretty high towards hermi.

Second question- Could be a different phenom than the others.

Third question - That seems pretty hot for mj IMO. I think you would be better off with just the potting soil and some perlite. 60% manure is way too much. I usually mix mine with 2 parts peat moss, 1 part potting soil, 1 part compost, and around 1 part perlite. Seems to be doing the trick for me.

Fourth question- I would transplant into a different medium and stop the watering. Thats way too much water. You are suffocating the roots. As Rusty would tell you that they need a wet dry cycle. That means water then let dry out. I usually water then watch the plants. If they start drooping a little and the pot is light its time to water again.

Like i say in all my posts, Im still new to all this. I could be right and i could be wrong but all your answers are on this site. Looks like you got some reading to do. Good luck.