How long would it take to get used to a fourteen hour time difference when crossing time zones

Depends, There are many factors that affect jet lag. You can get over it in a couple of days, or in severe cases, a week.

Here is some helpful info.

http://www.bodyclock.com/

You cant, as the most of a time difference you can have is 12 hours. If you have a difference of 14 hours then you have gone the wrong way round the world and you should then have a 10 hour difference the other way.
Besides that, I think it is really an individual reaction to time difference, I myself dont really suffer from it ( most i have gone is 6 hours difference) mainly because i work nightshift constantly so it is easier for me. On a whole I would suggest a few days. My tip would be when you get to wherever you are going stay up accordingly with the time of day where you are. If you get there at 10 in the morning, stay up to 10pm, likewise if you arrive at 10pm, go to bed

It depends, but you have to bear in mind that you might face differences in temperature or humidity percentage which would affect negatively on your muscles and your body performance.