You can cut the leaves but it's easier to take Excel, pull the proper dose up a needless syringe, get very close to the aglae and slowly squirt the Excel on it. If you have alot you can just do an area in your tank daily till it's all treated. When BBA starts dying it turns white/pink/red. Some stubborn areas might have to be treated right. Don't know the size of your tank but when treating with Excel, which is a liquid carbon to help with plant growth, you can spot dose with up to 1ml per 5 or 10 gallons (depending on what you feel comfortable doing). I use high doses of liquid carbon in my tank daily to aid in plant growth and photosynthesis so it is safe as long as used in proper doses.
As for feeding feed your fish in the morning, then after lights are out feed your nocternal fish. That is how I do mine. Fish don't need alot of food so be sure your not overfeeding.
As for lights 6-8 hours a day is all you should do. Extended periods of light just encourages algae.