0 we are not playing baseball.
2,like in every cricket match.
The umpires run a cricket match.
There are 4 umpires. 2 on-field ,1 TV umpire and 1 reserve umpire...
Field Hockey "referee's" are Umpires like in baseball.
Usually the umpires of a match.
There are 2 goal umpires, one at each end, 2 boundary umpires, one for each side of the field, and 4 field umpires. I believe some of the state leagues may have only 3 field umpires, but not 100% sure on that.
Never. There are no Umpires nor are there Penalty Strokes in hockey.