Almost everything he mentioned is good info but definitely don't raise your lights as high as they go. 24" at that stage is a good starting distance.
All the best to you and your girls
Make sure your room is sealed and get them temps around 85 if you want to see the results of the co2, also don't bother with 800ppm to straight to 1500.
Other then that looks like you have it under control. Best part is, if anything goes wrong you don't have a job to get in the way of fixing it...
Re-potting an auto generally isn't a great idea. They have a timed life cycle so any stress could potentially affect yield and potency. Next time start and finish them in a 3-5gallon pot depending on their expected size.
As for your leaves, it looks like potassium deficiency and can be brought...
Also looks like it stretched at the beginning and you buried the stem during transplant.
If the soil was over saturated for long durations as you say, it could have stem rot.
Absolutely,
If you're an experienced and knowledgeable cultivator you can get fantastic yields with amazing quality. It's guys with 1-5 years experience that always think more everything is better, and that's simply not true.
They get a bad reputation because outdated diodes are used in their products, regardless they are still much better than the blurples and for the price you can't go wrong.