your air venting is way off.
dosn`t matter were the light is you need to vent the whole room.your room needs to be a seeled room, without that you dont get proper negative pressure to vent the rooms and the fans arte kind of useless. bathroom fans cfm rating are not accurate. i feel they blow more than suck and thats not how you measurer cfm, fine for a small flouro grow but definately not a 1000.
do you have any pic`s, you realy should fix that up. if your walls are cardboard and you can move them how do you seal it and contain smells. it dosn`t need to vent outdoors or even far away, i have built cagbinets where my fan and filter were right on top of cab. intake and exhaust away from each other thats all