Some people use laptops for doing mobile work, and in some cases that work requires computing power and possibly external peripherals which might require power from the computer. And, of course, games are power hungry.
Higher wattage chargers can also charge the battery faster. Lithium batteries, regardless of their size, can be charged to full in one hour (but it's recommended for full charge to take about 1.5 to 2 hours to not wear down the battery). The bigger the battery the more wattage you need to charge it that fast. Especially if you are using the computer at the same time.
I believe Reddit said that only sexually explicit content would be filtered. Rest should be available through the API.