While the number of lights for a vanity varies, for an inch vanity you should look to have one or two lights. Avoid choosing fixtures wider than the vanity once installed, for balanced lighting. This will help to illuminate your bathroom setting.
Yes, your vanity does need vanity light. Vanity lighting is perfect for vanities because it provides illumination for you at all times of the day. This is especially important in bathrooms without windows for natural light. Vanity lights are also important because they add ambiance to the bathroom.