A:AnswerYes, you can use a higher wattage adapter for any Mac laptop. You can't use a lower wattage one without risking permanent damage to the battery. This information was provided by the Best Buy sales associate when I purchased my replacement adapter.
A:AnswerYes. It charges it pretty quickly from past experience. I would just advise as with any other electronic devices, do not leave it plugged in for extended amounts of time.