You put alot of time and work into this and thank you .Not a pro grower here but from what I have learned so far:
1. what type of lighting are you using? 24 hour light will cause alot of stretching if you don't keep the light close to the tops and won't grow as fast in my opinion. Are you limited on space? Some growers with limited height space will go 12/12 from the beginning to keep them low and eventually will flower without having to mess with switching the light schedule.
2. Once you water it's best to wait until the soil is dry before watering again. Depending on the temp of the room depends on how fast this happens. I started under florecent lights and only needed to water once a week once I switched to cfl's or hps light the temps were higher so I would have to water every couple days.
3.A fan too soon will dry your seedlings out and could cause them to break if the fan is too close or blowing too hard. It's best to wait until they are well established with 3-4 sets of leaves before introducing a fan. Once you do observe how hard it's blowing and make adjustments to the speed/position until it's just enough to make the do a little dance when it blows on them.
There are many different views on the above questions about lighting/watering I am just giving you what I have learned read and used myself that works for me.