4 years.
One weekend.
It depends on what you're running in the background while the iPad is charging. The heavier the software/app you're running, the longer it takes to charge. It also depends on how often you use the iPad. Over time, batteries tend to run down due to over-charging.
Depends on which iPad you have and how good your wi-fi is. I have iPad2 and it took me about 45 minutes.
Death.
fifty bajillion years
fifty bajillion years
find out yourself
3-5 days . maximum a week
.8928 hours
30 to 40 min max
At 50 mph, it will take one hour.