"I would've liked to have added perlite to the soil mix. Hoping to learn more about the possibility to add more to the existing mix before doing anything."
Defintely.. perlite or similar should be 50% of volume. With coco, you can drop to 30% because coco holds less water per volume. A little less is no big deal, too. Best for roots and growth but will increase rate of irrigation.
2gallon pot may need more frequent irrigation at end, possibly daily, but doable. Better in a soilless context though.. toward end you may have to treat your soil like a soilless substrate and provide everything each irrigation for best results.
pH in soil is usually easier to handle. it's good to pH balance anything you add, but many don't bother. They are probably lucky with some good tap water or RO system. 6.5-6.8 .. just keep it under 7, but even 7-7.5 won't be the end of the world in most cases. Still, keep it under 7 to be safe.
Watering - change your perspective. this requires a little hindsight but after 1 cycle you can calculate it and mix up what you need with limited waste. Don't give a specific volume you choose. you give what it needs when it needs it, and you use the weight of the pot to determine when to irrigate. Allow top 1" to dry, feel weight of pot and irrigate until you get mnimal runoff to ensure the entire thing is wet. Dry pockets are no good over time. Repeat that process and be familiar with low-weight level... you'll find the volume on next irrigation that you can plan for per pot... then mix appropriate volumes based on that when fertilizing.
You can irrigate more frequently (ie before "1" deep" dries), but always make sure some dryback occurs. if perpetually too wet it invites all sorts of problems. This is where the 50% perlite would pay off. With potentially big plants in small-ish pots, you'll know when you can get away with an early irrigation rather than let it sit overnight or something.
As of day 6 that cfl seems to be doing well-enough. You can tell be internode distance -- length between growth nodes. If it stretches too much, you need more light. If it remains too compact, you need less light. Early on, you'll start low and ramp up as you observe the plant... While it won't be exactly the same for every plant, it'll be in the same ballpark. Take notes until it's memorized or comfortable observing/reacting.
if far enough away and dimmed properly, can use the 100w sf light anytime you want. no matter what, you adjust to whet the plant dictates. This way you can really gas it when they ask for it and avoid damaging any that may take a bit more time to handle it.