Very nice! I like the rock arrangement!
First tip, You have quite a lot of surface agitation. All that surface agitation is letting co2 escape (pretty much making injecting the co2 pointless if it all gasses off). Reduce agitation to just a light surface ripple (you might need to increase surface agitation for more oxygen once fish arrive).
For the co2 levels. Use a KH/PH co2 chart.
CO2/pH/KH table - Aquarium Plants - Barr Report
Most shoot for a 1 point pH drop (ph 7 without co2, to ph 6 with co2), to have co2 concentration around 30ppm.
Since you are doing a DIY co2 set up, I am pretty sure you are inject co2 24/7, so you would want to test pH and KH from your tap water (let the tap water sit for 24 hours or run an airstone in it to off gas the co2 within it) and then test the pH and KH of your tank water. As mentioned, most go for a 1 pH drop. I haven't done DIY co2 so I don't know how achievable that is.
Make sure to post another thread again before you add fish, just to make sure all the dangers are addressed before you go about adding fish (too much co2, or too little oxygen can kill the fish).
The emersed leaves will melt off (you can go ahead and cut the decaying ones off) and submersed leaves should slowly start to grow while the plant transitions.
I'm not very knowledgeable on lighting, but I think it sounds strong enough to grow all your plants.
Around 6500K (cool white) is the general Kelvin/temperature bulb most use on planted tanks. 10,000K is more for saltwater tanks if I'm not mistaken. But hey, I am sure it still works and the color of light emitted doesn't look bad at all. The Kelvin is really just for visual appeal in the color emitted for the most part though, so it's more so personal preference.
Can't say I know what the rocks are. Don't think it looks like any granite I am used to seeing. You can test it by having water (tap) with know pH, KH, GH, then place the rocks in the same water and seeing if pH, KH, or GH rise. If they don't it's inert and safe. If it does rise, you water can get "harder" and/or more alkaline. Not always a bad thing, but not always desired or preferred for most applications. Another way to test is to drip an acidic substance on the rocks (out of water) and see if there is a reaction (will fizz/produce bubbles). Some use white vinegar, but it's not that strong of an acid, so some use Muriatic acid, but do be careful in handling. If no fizzing, the rock is inert/safe.
You could probably do with using more root tabs, 5 is not much really. People often use Osmocote+ as root tabs (cheaper and better). It would be recommended in getting dry powder fertilizers. You can get dry ferts from Nilocg, a member on this forum. He can advise you what to get (micros and macros - NPK and CSM+B).
For the DIY co2, I'm not sure if the lines are getting kinked/folded, or if they just need to be placed lower to have more up lift room to create enough pressure to push through the diffuser.
Regarding the surfactants in the ammonia product, I have no idea really. It's good you had the activated carbon/charcoal (chemical filtration) as that would of helped remove it out of the water. Not sure if the surfactants would kill the beneficial bacteria or not. I don't know if they would have absorbed into your substrate making your substrate toxic/retaining the toxins in your tank/water. I guess the only way to find out is after you add fish. So I would get only one or so "tester" fish before getting all the other fish, just to make sure it's safe.
As for pH range, I like to have it generally at neutral (pH 7) to slightly alkaline (up to 7.5). With a 1 pH drop, 6-6.5 would be alright. I personally wouldn't keep inverts (snails, shrimp) in that acidic water range though. Yeah, many have/do keep inverts at the mentioned water parameters, but still, it is acidic and not so great for their exoskeletons. I guess if you had naturally 8-8.5 pH and 1 pH drop to 7-7.5, keeping most inverts would be fine.
The nitrIte test actually looked to have some detection, was the turquoise/teal that 0 ppm is. Good thing as far as cycling goes (ammonia converted to nitrite). The Tim's One and Only bacteria is the nitrfying bacteria, so dosing that is like jump starting the cycling process, so you can add fish much sooner than normal.
By the way, great "How to change valve stem caps" video. Very helpful

hahahaha
And oh yeah,
GO HAWKS!!!!