Looking great brother.
Sorry I got so long winded here....
I prefer to have the temps below 80 and above 65f. RH above 45, below 75, I know that's a wide range and to some those numbers are all wrong but for my situation that's what I have to deal with. Outside humidity regularly below 20% RH. The plants DO NOT like the low humidity, I have not found the magic number for max RH. Some say too much will decrease yield and quality? I know for a fact too little RH and too high temps (90f+) will ruin your crop, not just low yield etc. but ruin it. Only good for hash if that, haven't tried it with the rag weed.
If it's over 80f I start freakin out and will start looking for a way to cool it down immediately.
I"m not sure why you want to trim leaves? They are what transfers the energy to the plant so to speak.
Me personally, I would wait til they are bigger and they will benefit more by shedding light on the lower buds at that point.
The topped plants will take a little longer to mature due to the set back of having it's head cut off. Not a fan of topping. LST I believe is the best compromise, makes them bush out but doesn't set them back like topping does, and I don't lose that top.
What I would suggest you do: Mix up a batch of neem oil spray, mix it 2/3rds strength and only spray the dirt and bottom half of plant. I don't like spraying it on the tops just in case the plant doesn't like it. If you spray the whole plant, only spray the solution at %50 coverage, do not saturate. Just a fine mist over the top and STOP spraying. I feel you can clog up the stomata with the oil if used excessively. Spray the neem every day for a couple days and then go to every other day for a few more days and then every third day. Do not spray the neem on buds, I can't imagine that being very tasty.
Neem does not kill bugs, it's a natural deterrent and discourages the bugs from nesting in your soil or on the leaves. (spider mites). Preventative maintenance goes a long way in horticulture.
Microbelift dot com has a mosquito product that I add to every gallon of water, one drop per gallon. (swear by this stuff) No bugs since using this product, I take that back, a few here and there but they don't stay. I believe it's organic and basically either the micro life eats the larva or makes it inhospitable for the gnats and other bugs to lay eggs.
The fungus gnat will burrow into the soil, lay eggs, and then it will feed on the roots and finally come out and fly around, so, by the time you see them you already have a bigger problem.
I also use the sticky traps that unroll out of a small tube and are sticky as hell, put them away from direct fan so the bugs can land on it and stay there..
If you get thripes you have powder mold also, they go together.
For PM (powder mold) I use a sulpher pot and burn it every so often, once a week or so, lights off, burn for about an hour or so and keep the pot away from the plants by at least 5 feet. A direct shot of vapor will damage leaves.
If you have an old coffee pot you may try using that for your burner and then all you'll need is the sulpher pellets to melt in it. I have not tried using a coffee pot, I bought the burn pot at the same time as the pellets. However, I believe a coffee pot is about the right temp. I can do some checking with a temp gauge to find out how hot the burn pot gets and also check my coffee pot to see where it is. Will have to report back on that one.
BTW, the sulpher smells terrible but it works. They say you can treat with sulpher during bloom and I have but I wouldn't use it near harvest unless I absolutely have to, because of a mold/mildew issue. During veg is the best time to treat with sulpher.
I would definitely exhaust the A/C outside. CO2 falls to the bottom of the room so I would just make sure all my exhaust vents are up high, as they should be anyway to exhaust all that hot unusable air. Tip the exhaust intake up to get the hottest air out. Intake low, exhaust high.
This is just me thinking out loud.....................
I think you're going to do very well if you can keep everything in check and diligent about bug removal/prevention.