That's a marvellous DIY setup brother Yaz. Let's see if we can dial it in.
Temp and humidity are good, perhaps a tad wet for bloom. But you're in the Veg stage, correct?
Light placement looks okay, maybe a little too close to the wall. Is it covering the girls evenly? Is there any way to raise/lower the reflector or slide it over? If not, you may need to rotate the plants themselves periodically for even distribution.
How is the exhaust set up? Got any kind of fresh air exchange when the door closes? They need circulation if it's not already in place.
One last question: How are you preventing drainage from running down to those wires beneath? That seems a rather hazardous position for electricity.
Any kind of circulation you can give them is better than nothing at all. But I think you need a 6" fan in there at bare minimum.
Drainage is going to be a complication if you're saturating those bags properly. You need to give them a good rinse now and then to wash away any excess salts from the bottom, which build up over time and can become poisonous. If you can't move or insulate the wires, find a way to collect runoff so you can then dump it. I use 12" horticulture saucers like these pictured.
One thing I'd like to suggest instead of trying to support lanky stems, you could try covering them with a sprinkle of dirt, while mixing up the top soil with fingers to give the roots a breath. You'll feel if there's any compaction and it'll help distribute the moisture with oxygen. A good exercise to practice every few days in between waterings.
I try to get soil all the way up to the cotyledons - the baby leaves - even if it means bending them over some. This way, the plant will be in better shape to support itself during bloom.
No! If they are auto, then flowering will begin automatically - when the internal genetic clock tells the plant she's mature - regardless of how large or small she is and independent of the amount of light received. We can give Auto plants 24 hr. light all the way through its life, and she will grow larger the more you can give.
Any less than 18 hours, and yields will begin to decrease. Only photoperiod (regular) cannabis should be grown in 12/12 conditions, which it needs in order to trigger bloom.