It depends. Age of cataract is not as important as vision loss and potential vision improvement. If your cataract has caused worse vision over the last few months or years then it is appropriate to have it removed. If the vision in that eye was never great and does not seem much different, there may not be a benefit in removing it. Speak to your eye doctor and have a thorough examination before deciding.
Maybe. A congenital cataract by definition means it has been present since birth. Having cloudy vision while the eye and brain are developing before age 8 can cause irreversible vision loss due to amblyopia. So, you may not experience total vision restoration with cataract surgery. If you do not have amblyopia, i would expect a great result from cataract surgery. Your surgeon should be able to guide you.