ballasts exist to regulate the current for Lights, however CFL's are self ballasted, so no need for them.

6500K is good for veg, 2700K for Flowering.

Carbon Filters usually last about 9 months (ish)

you can do anywhere from 18/6>24/0(18/6 promotes better root growth, 24/0 promotes slightly faster veg growth) until the plant is half to a third of the size you want your final plant, they will double/triple in size during flowering