There's already a circuit for the washer and dryer. I don't think I should be using it anyway. Or can I?
No, let it alone. The laundry circuit should be dedicated under the current code.
Yes, go with the GFCI, even in the lights if possible. Though someone my mention that fluorescents could cause nuisance tripping, I have not found that to be the case with the new electronic (instant start) balasts.
