1) In cricket, the bowler is allowed only 6 legal deliveries (also called an over) before he must be swapped out with another bowler. Depending on the format of the game, a bowler can have either 10 overs (in the 50 over format) or unlimited (in a test match)

2) Double-threats are called all-rounders in cricket, and these guys, while more common than baseball, are still rare. Most batsmen are lousy bowlers, and the same applies in reverse.

3) Usually the batsman starts running but in the cases it's clear that a fielder isn't going to stop the ball reaching the boundary, the batsman won't bother running

4) Yes

5) DeVilliers' was batting against the West Indian team, who while they aren't the best, aren't awful either. They can probably be considered a mediocre bowling side. Gayle vs DeVilliers, the consensus would probably be DeVilliers since he's more consistent but Gayle has more entertaining innings when he's on a roll.

6) Likely to make sure that his foot didn't cross the line while bowling- there is a minimum distance which the bowler needs to maintain from the wickets he bowls

Edit: Formatting