I love my cobs....
Here's some info BigSmo at Cobshop.net gave in a converstaion last Summer:
As far as height goes numbers are very basic and should only be used as a starting point.
Every strain is different, nutrient schedule, even how well you grow the plants makes a big impact.
For seedlings 30-36” in veg 24-30” and in flower 16-24” is the safe zone.
If the plants are green and happy with leaves pointing upwards then you may consider lowering a bit more.
Yes the lights should remain 30-36 when you first plant them.
In the early stages they seem like they can handle more light so it’s hard to draw that line of too much.
As far as light schedule goes this is all personal experience or opinion.
I run my lights 24 hours a day till the plants are a few inches tall than switch 19 on and 5 hours off.
I keep it here till finish. I also set the 5 hours off between 12-5pm.
The warmest part of the day helps cooling and the warmer part in winter so they plants have less shock during lights off.
"When the seedling is first planted under the dirt I should have the cobs 30-36'' from the top of the pot?"
Yes.
Technically you don't need light until seedling breaks ground but I recommend using them anyway, in order to dial in temps, if need be.
There is no need to adjust lights until the plants show signs of need, for a tweak.
For instance, if your seedling starts growing tall and lanky, you may consider dropping lights or raising pots.
You will be better off with lights being too far away than too close.
Seedlings do not need much light, you can fire up (2) AutoCobs for now, which will help keep your heat down; I recall your spot to be quite warm.
"Please provide on / off times for the 3 growth phases."
This question is a growers decision. It has nothing to do with light source.
You want at least 18hrs on, 6hrs off, 18/6.
The most popular autoflower light schedules are 18/6, 20/4, 24/0.
Me personally, I prefer 18/6 in the warmer months, increasing on times gradually, daily half hour increments, for colder days to come, where I will finally settle on 24/0 for winter.
Light cycle for autos do not NEED to change throughout the grow, I do, merely to keep environment stable.
This is something you will get a feel for.
Hope that helps!