1.i dunno havnt really looked after i killed it

clean yes,but a slightly lower % of cloudy,but i wouldnt worry much about that its a % afterall.
harvest is a harvest window.a period of hmm maybe 1-2 weeks.anywhere in the middle is good +/- a f days for personal preference.
2.big round ones for power cables and or ducting.flaps with screens is to regulate temps/humidity/airflow if needed.
with so many lights its a bit of play about and see 36" is common starting ground.wait and see if the seedlings get leggy or stay squat.
use the @ a lot and quote folks so they get an alert like
@rick-j 
i have no idea what im talking about im an eejit so dont quote me