My CFL's are all 100 watt equivalent which is I think 23 watts each. I have 9 of them, pluse 3 flourescant tubes at I believe 18 watts each.

Using the fan to strengthen the stems is a very good idea.
And as for plants sleeping, its the same as you and I. We still breathe when we are sleeping, so plants do as well, only at a reduced rate, just like us. So yes, ventilation is important even when the lights are off. Some will say its not, but I've always kept my ventilation system on 24/7.