1. Night only lasts like 15 or 20 mins. Its not too bad...just turn up brightness on your monitor a little or make sure all lights in the room you are playing in are off to reduce the glare on your screen.
2. Buff guns are not more powerful. The fact that buffs have multiple guns that all track on same target make it seem that way. Also, if you attack a buff from dead 6, he has greater range with his guns simply because he is flying away from you and the bullets are coming toward you. Learn to attack buffs from head on or 10 to 2 oclock and you will do much better against them.