Wow, everybody's shit looks tight!
As for top watering, it's totally fine, however, in the early seedling days you want the plant to know that survival means it needs to send a nice taproot downward, and topwatering can slow this process.
Manures in the mix are ok if the animal is that shat it is no larger than an earthworm, is my rule of thumb for SIPs and its coming from experienced organic SIPpers. I'm running a 1 part wormcastings 1 part peat, 1 part perlite SIP right now and have done in the past and it works well but they are my own very customized castings. I don't think storebought would get through flower alone, but I could be wrong.
Promix off the shelf is about 70/30 peat/perlite. So I add extra perlite to make it 50/50, then add half of that total volume in worm castings, resulting in three equal parts (by volume) of each. Remember though, I'm using a lime-buffered peat/perlite mix (Promix, Sunshine Mix #4), so just adding raw, unbuffered peat, and your own perlite and castings, wont get you the same result. You need the buffering of the lime in the finished peat products, though you can go DIY on that too but I can't instruct you there.
These plants are in DIY 27gal tote SIPs, rez is 6gal. I drop 2, 10 gallon square Geopots in the SIPs and this keeps from being over wet and I have 10gal of soil for each plant so I can go organic. I use precut black plastic laid on the soil top for organics so I draw roots up to the top as I will amend by laying pure castings on top before flip and after. I’m also using an airstone in the rez for organic grows just to make sure nothing anaerobic starts forming in the rez, not worried about dissolved oxygen levels otherwise. Really like this method. Yeah plants are close to each other but simple training keeps things civil. Sauga- view
Co2 bags can be pretty helpful, try to mount them as high in the tent as you can as not only does the co2 fall down but the warmer temps generates more co2. It's just mushroom farming 101. Over 84 deg F might be pushing it, however. Follow the bag's instructions. It is a supplementary product, and approx. doubles your background cO2 which does benefit and does not require, or benefit from, hardcore light values. It does help the plant, however. In the pics below you'll see I'm offgassing my fresh wines in the tent for the plants benefit. Same deal. (I cover them from the lights, they're uncovered for the photo only.