You want to wait until 70-90% of the hairs go amber. Consider buying a jeweler's loupe. They're cheap on Amazon. The trich test is more accurate, but most people still just go by the hairs.
They might just be getting used to the new lighting, wind, and humidity. You may have to feed more if it's been dry out. Also check for pests, but don't take any serious actions unless it gets worse.
She broke the surface about 9 days ago. Shes a GG auto. Appears to have some new growth but shes all sorts of fucked up.
Try to save her or replace her before it's too late? I have 4 growing in DWC buckets in my tent now, all same strain and age.
I dont top, but the concept as I understand it is to keep the main cola from getting too high, thus maximizing light to all flowers. I'm sure people top other spots for the split and extra bushiness quality though.
Also, you can snip the fan leaves when they start dying. They're taking up energy at this point that you really want going into the buds, but only cut the dying ones for now.
Looks like she still has another 10 days or so. You want to have 70-90% red hairs vs white. Harvesting now will give you a nice light high, good for morning and housework, but lacking that hit-you-like-a-freight-train quality we all love.
I would be willing to bet it's much warmer than 78° at the tops of your plants. It's only a slight curl so I would guess you're hitting 83° or so. Find a way to test the temp up at the top of you plants, either just hold your thermometer there for a few minutes or move the lights up a couple...
I wouldn't change anything yet. If you just fixed your pH, give it time. If the discoloration doesnt spread, you're good. Hard to tell under the blurples, but I would bet if it's something else it's nitrogen deficiency.