Cannabis flowers based on the amount of darkness it receives, so you can decrease the day time amount and be fine when flowering . Next time, turn your lights off early at 9:30 PM, then back on at 930 am. That should do the trick
1. I think CFL's aren't supposed to produce a ton heat, so I'd imagine 2 inches would be fine. I'd double check this though.
2. I'd go with 6500k for veg, 2700k for flower.
3. I have no idea about heat but I'd imagine the smell would get pretty strong after a while, especially with no carbon...