Nice thread. Read over it several times. Been smoking a little this morning too so bare with me.
There is a member named Carty here. He is not the king but he is definitely one of the princes of growing auto flowers. I can not believe he hasn't chimed in.. You usually catch him on really late and early morning hours lately.
Second thing I caught or may have missed - Is - I am pretty sure they need a little darkness for stuff related to photosynthesis. Even though you are growing automatics - I would do either 20 hours on - 4 off or 18 hours on 6 off. I stand to be corrected on this, but I would not go for the full run at 24hrs lighting.
Third - This comes from your very first post !!! - Hydrostore - I no longer 100% trust my hydro store workers or the owner. I did at one time. From fighting a bug infestation when I first moved to the passion, through pump options, and especially nutrients. I have enough quarts of nutrients to fill the floor of a 3' by 6' room with fixes and you need this or you gotta have thats. They went from being hippy fellow grow buddy's who I would trust as much as anybody here - to being just a bunch of salesmen and buyer beware. Not saying you hydro people are like that but... Anymore - I double check anything they say - SO if you have a problem or question MY advice is to bring it here first.
Any way - Nice read I'm pulling up a chair.
@Carty
That's a lot of words !!!