At behind stump.
The umpire stands in foul territory behind first base
The Umpire-in-chief stands behind the catcher. First base umpire stands near the foul line behind first base. The second base umpire stands towards shallow center behind second base. The third base umpire stands the same as the first base umpire. They don't necessarily have to stand in one spot. They can move wherever it is necessary for them to clearly see the game, as long as it doesn't interfere with any of the players or the ball in play.
Yes, as long as he does not interfere with the base runner.
There are two umpires for a game of rounders, one for the batters and one for the bowlers. The batter's umpire will usually claim a spot between the batter and the first post, a few steps back from the field. The bowler's umpire will stand where he or she has a clear view of both the batter and bowler. Most often they will pick a spot behind the second post or between the second and third post.
If the first baseman is making a play on a batted ball it is the responsibility of the runner to yield. If there is contact the runner may be declared out. If the first baseman is fielding a thrown ball and there is contact the umpire will usually call the play as it happens and consider the contact incidental. If the first baseman is standing in the baseline while making no play on the ball, he can be legally knocked down and the umpire can rule that the contact prevented the runner from advancing and award as many bases as he determines. That will generally just be one extra base unless the runner gets up and reaches second safely and is thrown out at third. When the contact occurs the umpire should have his hand out in a fist signifying that there has been obstruction and then make his ruling after the play is over. No base will be awarded if there is a runner on first when the batter hits the ball and said runner cannot reach third safely. In this case the contact becomes moot as the runner on second may not be awarded an extra base for obstruction on a player behind him. Many teams put a big kid at first to stand in the way and delay the runners. If an appeal to the coaches and umpires does not get him to move then your players will have to run him over or take the contact get up and try for the next base. If the first baseman is just plain "purposely" blocking the bag as the runner has arrived and the ball is on its way but not there yet the batter should be awarded first base.
Visualise a table from above. The umpire sits and looks straight ahead, across the net. Sometimes there is an assistant umpire, who sits opposite the umpire.
Behind home plate, at 1st base, and at 3rd base. Some leagues also have a 2nd base umpire.
usually 2. They stand at different sides of the court to one an other. One umpire controls one half and the other umpire controls the other half.
usually behind or right in front of second base but almost always behind
The person who you are thinking of would be the umpire standing at the non strikers end. They stand about one meter or so inline with the stumps as to give them the best view of the batsmen's stance in relation to the stumps and the keeper. This gives them the best possible chance of making the correct decision when it comes to an lbw or caught behind appeal. There are many other officials who oversee the game, with the other on field umpire being the square leg umpire (who, unsurprisingly, stands at square leg). The main umpire and the square leg umpire take turns in the relative positions. There are also the people who hold the official of positions of third and fourth umpire, but they are not on the field of play.
That place is called the umpire where the man makes the call safe or out